First off thank you for the mod. I like the general idea of adding tiers to machines where they seem to be missing.

There are a few things related to tungsten smelting rework that seem a bit off though:
1) Zinc powder recipe has no ingredients. This definitely seems like a bug.
2) Second tier of tungsten carbide process is less effective than the first tier (produces less tungsten carbide per input tungsten ore). The processes have effectivity rate of 1, 0.75 and 2 for tier 1, 2 and 3 respectively. This seems a bit off and I'd suggest doubling the output amount of tungsten carbide for the second tier process.
3) Smelting of tungsten with copper into molten alloy metal is done in chemical furnace. For all other molten metals it's done in induction furnaces. I guess this is because the process has a fluid input, but it doesn't seem to fit consistently into Angel's processes.
4) The reworked tier 3 tungsten smelting seems to increase the yield more then usual. Normally the processes have effectivity rates of 1, 1.5 and 2 for tiers 1, 2 and 3 respectively. But for this new process it jumps up to 3.75. I am aware that it uses quite a lot of additional manganese, but it would be more in line with other Angel's processes if the addition of extra metal would happen in one step (when adding cobalt, nickel or zinc) and not before.

Also regarding the addition of tier 0 of constructions blocks:
1) From what I see due to this change the tier of construction blocks used in recipes across all original Angel's content has shifted by 1 down. E.g. chemical plant 3 normally uses construction block 3 and with your mod it's construction block 2 instead. This seems like a drastic resource cost reduction across the board and I think it might need some rework.
2) Construction block 0 is not used in tier 1 recipe which is inconsistent with all other block recipes. I'm aware that simply adding it to tier 1 recipe would almost double tier 1 block's cost, but IMHO there should be something done about the building cost to match Angel's original costs more closely. I think this should be addressed together with the previous point.

Then I have a few suggestions:
Since the mod adds tiers of buildings, would you maybe consider adding an extra tier of normal trains and maybe an extra tier or two of armored ones?
And if you did extra tiers of warehouses, would you maybe consider adding extra tiers of fluid storage? I mean higher capacity pressure tanks.
Maybe extra tiers of fluid voiding buildings (flare stacks and clarifiers) and cooling towers? Faster clarifiers would especially help my designs.

Tungsten rework:
1) I've fixed the bug for zinc powder, that was supposed to be crafted out of zinc ingots and when I fixed the tabbing everywhere I guess I accidently erased it. :)
2) I've confirmed this and I agree that doubling the Tungsten carbide powder mixture output would be the best way to do this. Halving everything to have consistent powder outputs is messy, since one of the inputs is odd. I'm going to double the time requirement, however, so you still have the 3/2 powder/s ratio. I've also added numerals to the icons so they may be more easily distinguished.
3) It is possible to inject an input fluid box into the induction furnace and allow for the recipe to be done in an induction furnace. I will see about doing this.
4) I'm not very familiar with the involved production chains to comment on this one.

Construction blocks:
There is some shuffling of ingredients going on, it's not a straight demotion:

local block_ingredients={
    ["block-construction-0"] = {new = "stone", old = "stone"},
    ["block-construction-1"] = {new = "stone-brick", old = "stone"},
    ["block-construction-2"] = {new = "clay-brick", old = "stone-brick"},
    ["block-construction-3"] = {new = "concrete-brick", old = "clay-brick"},
    ["block-construction-4"] = {new = "reinforced-concrete-brick", old = "concrete-brick"},
    ["block-construction-5"] = {new = "titanium-concrete-brick", old = "reinforced-concrete-brick"}
}

It looks like the intention behind this was to add a 5th tier of construction block by adding a 0th tier and then moving all the recipes down one, then downranking. The other key component in construction blocks are the construction frames, and those aren't adjusted at all, and I think they'd need to be downranked as well to compensate.

I think ingredient wise, they're supposed to map like this:

0 = 1
1 = 2
2 = 3
3 = 4
4 = 5
5 = new

But this is only half-accomplished, since construction frames are left alone. I can build a new way to map these so that blocks and frames are appropriately remapped (icons as well, since the icons match the ingredients). Adding a construction frame 0 and shifting the ingredients down would mean that a CB2 under EA == CB3 under base, so the building costs shouldn't change. It does mean we'd need to come up with something for a new CF5.

So a proper remap would be something like this:

Construction Block 0    3 Stone             1 CF 0  
Construction Block 1    3 Stone Brick       1 CF 1      1 CB 0
Construction Block 2    3 Clay Brick        1 CF 2      1 CB 1
Construction Block 3    3 Concrete Brick    1 CF 3      1 CB 2
Construction Block 4    3 Re Con Brick      1 CF 4      1 CB 3
Construction Block 5    3 Tit Con Brick     1 CF 5      1 CB 4

And construction frames would do something like this:

Construction frame 0    1 iron grate        1 girder
Construction frame 1    1 steel grate       1 girder    1 rivet
Construction frame 2    1 aluminium grate   1 girder    1 rivet     1 bracket
Construction frame 3    1 titanium grate    1 girder    1 rivet     1 bracket   1 plating
Construction frame 4    1 tungsten grate    1 girder    1 rivet     1 bracket   1 plating   1 strut
Construction frame 5    1 ??? grate         1 girder    1 rivet     1 bracket   1 plating   1 strut     1 ????

Would need to add two new components, the question is what should those be. I have no real familiarity with the overhaul. Oh but there's all these other blocks, fluid/electronics blocks that have knock-on effects if I tweak CFs. Looks like the electronics blocks just need to have their frames downranked 1 under the proposed system... though EB0/EB1 share CF1?... And the fluidblocks, hm. Mechanical blocks... this will require some thought.

Extra buildings/trains:
When you say normal trains/armored trains, are you referring to the ones added by Bob's mods? The angels ones already have tiers.

Extra tiers of fluid storage is probably fine, and flare stacks/clarifiers/cooling towers could be done.

I think the issue with adding an extra tier past current tier 5 is that there are currently no materials in Angel's mods to support it.
There are 5 main tiers in Angel's mods currently and they all have their own "construction metal" and "electronics metal":
Tier 1: iron/copper
Tier 2: steel/tin
Tier 3: aluminium/silver
Tier 4: titanium/gold
Tier 5: tungsten/platinum

Introducing a new full-fledged tier would basically require addition of extra materials or designation of existing materials for that tier.

But there's also tier 0 of circuits (grey) and electronics blocks. The blocks have simpler recipe (no cable harnesses, no battery) than other tiers and also the circuit is not a true circuit, just a circuit board. But they basically do use all materials from tier 1. If this mod wants to add a new tier of construction blocks it could be tier 0 like it does now, but the problem is with how simple its recipe is. The way stone/bricks are used now within this mod seems good as basically stone goes to tier 0 and it's basically raw material and tier 1 through 5 then use crafted bricks. It's just that construction block tier 0 recipe should probably be simpler version of tier 1, but these recipes literally don't use anything other than a construction frame and stone/bricks. There's no room for simplification.

If the mod kept the recipes as they are now but tier 1 construction block recipe would use an extra tier 0 construction block it would increase iron usage across the board (2 iron construction frames instead of 1 for tier 1 and above) and iron is already the bottleneck in all stages of the game from my experience. So this wouldn't be a good solution either. The problem with iron stems from the fact that tier 1 and 2 construction metals are both iron based - tier 2 is just more expensive iron. So within the solution which you proposed (introduction of a new construction metal for tier 5, shifting original tier 2 through tier 5 construction metals one tier down) I'd make iron a tier 0 and steel tier 1 as iron is basically just a crude version of steel. Tier 0 construction frame could be a simplified version with fewer materials to decrease the overall iron usage and complexity of tier 0 process. And I'd remove iron girder from all construction frame recipes. But this would probably require quite a lot of work and it'd mean drastically reworking how Angel's mods' metals are used because the construction metals are used according to tiers in various components such as weapons, motors and mechanical parts.

And if you are considered this then maybe I'd keep tungsten tier 5 as it is quite complex and probably introduce a new metal between steel an titanium. There's nickel and cobalt, which are quite plentiful in Angel's games from my experience and there's not that much use for them other than additives into construction metals. In Bob's mods they are used for alloys, but Angel's don't favor alloys too much. But yea, this would be quite big revamp.

And as for the trains - yes, I meant new tiers of "vanilla" trains and armored trains. I kind of forgot that they are coming from Bob's and I guess extending Bob's mods is not in the scope of this mod.

Anyway, thank you for the detailed analysis, I appreciate the work that was already put into the mod and also the fact that you're trying to address all the things that I brought up. I'm playing a game of expensive Angel's/Bob's for almost 9 months now and I'm considering adding this mod into the mix as it seems really cool, but the construction block rework seems to cheapen buildings a bit too much for my tastes right now. Anyway after al these months of planning out my production chains I'm quite familiar with most processes of Angel's so if you need any assistance I'd be glad to help.

The "problem" that EA is trying to solve with the construction block shenanigans, is that a small handful of buildings come after Tier 5 and are effectively Tier 6. (I ran into this issue when supporting them with my reskin mods). EA has bobplates as a dependency, so all the materials that Angel's doesn't use that Bob provides are available for a tier 6. And technically speaking with Bob involved tungsten is a tier 4 material, as you have copper-tungsten/nitinol as a tier 5. Angels doesn't really use these materials though in the overhaul (or at all...) which I know is something they want to change but it's not really urgent for their dev team.

Given the lack of integration for Nitinol/Copper-tungsten, I'm not sure they'd make a good tier 6 material.

Points 1, 2, and 3 are now addressed as of 0.4.5.

OK... lets get a quick dump down here:

| Tier | Metal     | Brick            | Electronic | Wire 
=======================================================
| T0   | Iron      | Stone            | Grey       | Copper 
| T1   | Steel     | Stone-brick      | Red        |  Solder 
| T2   | Aluminium | Clay-brick       | Green      | Tin 
| T3   | Titanium  | Concrete-brick   | Orange     | Silver 
| T4   | Tungsten  | Reinforced-brick | Blue       | Gold 
| T5   |  ??       |  ??              | Yellow     | Platinum 

If i wrote the above replacement script correctly, it should be basically adding in the new tier of construction block (block-0) to align with the existing list (tier 0 for "unlocked from the start". Adding the titanium brick to tier 5). The shuffle down a tier and as you have most likely seen, it does drop the materials down a tier, so steel drops to iron etc.
In terms of the ingredients tweaks, i don't think the lower end is that bad (except possibly dropping the steel cost of some buildings which would otherwise be locked a bit later).