Seed 322322322
Percent Randomized 100

Offshore pumps cannot be crafted by hand and are required for gears.
Both assembling machine 1 and 2 require gears or pumps, so auto 1 and 2 are locked.

Small electric requires pumps, which is required for science so cannot proceed up the science tree even if I wanted to long shot for assembling 3 hand crafting.

I believe the logic required would be making sure assembling machine 1 path to build cannot require a "cannot be crafted by hand" or to have a physical resource available. Or I suppose starting with a single burner assembling machine, if you wanted to add a safety item.

Where are they crafted, then?

21342322

Immediately after, I had to laugh.
Electronics research required crafting 10 burner inserters to unlock assembling 1. Burner inserters had "Cannot craft by hand", so the buck stops there.

That one might be an easier seed to debug on.

I can't open factorio at the moment; it sounds like they might be crafted by furnaces, can you check the tooltip to see?

No, you're right, I'm just missing that small local step entirely.

Oh, so it's all good? Just need to chuck some things in a furnace in both seeds?

It's purely user error, I went back to the previous seed to confirm. Sorry about that.

I was treating the "Craft in" as white noise, it seems. Questionable choice for a randomizer, especially one I've played years before as well.

It can be counterintuitive; I've seen others make the same mistake, so it's something I would change if I could. Maybe put smelting things in a new tab with the label "smelting" just to make throw it in people's faces. Or at least in intermediate products. XD