I made adjusted recipes to have the mod work with Seablock:

require("prototypes.classic_beacon")
require("prototypes.item")
require("prototypes.entity")
require("prototypes.technology")

data.raw["recipe"]["beacon"].ingredients = {
    {"electronic-circuit", 200},
    {"advanced-circuit", 200},
    {"crystal-splinter-harmonic", 10},
    {"copper-cable", 200},
    {"steel-plate", 200}
}

if settings.startup["wret-overload-enable-beaconmk3"].value == true then
  data.raw["recipe"]["beacon2-recipe"].ingredients = {
      {"beacon", 1},
      {"electronic-circuit", 200},
      {"advanced-circuit", 200},
      {"processing-unit", 200},
      {"crystal-shard-harmonic", 10},
      {"aluminium-plate", 200},
      {"tinned-copper-cable", 200}
  }
end

if settings.startup["wret-overload-enable-beaconmk3"].value == true then
  data.raw["recipe"]["beacon3-recipe"].ingredients = {
    {"beacon2-item", 1},
    {"advanced-circuit", 200},
    {"processing-unit", 200},
    {"advanced-processing-unit", 200},
    {"crystal-full-harmonic", 10},
    {"gold-plate", 200},
    {"titanium-plate", 200},
    {"insulated-cable", 200}
  }
end

It is necessary to basically reload the whole mod in data-updates.lua or data-final-fixes.lua to overwrite the changes to beacons from Bobs and Seablock which they only start doing in the data-updates phase.

I also made a minor change to your technologies and removed the upgrade = "true", line in both techs as otherwise they remain hidden until the previous effect transmission tech is researched when searching for them in the tech screen.

Full zip with all changes is here: https://drive.google.com/file/d/1aHC29Pd2T2R6ICcYsQJgBUhxwbH3cEuc/view?usp=sharing

Does this do what you want?
https://drive.google.com/file/d/1QQOy6r3cp3y3AgLBA5gK1IALTiHpZHYK/view?usp=sharing
I made some changes to the Bob's beacons, but they shouldn't affect your builds in any negative manner. I also didn't change the regular beacon's recipe, because 10x the cost seems excessive.
If you have no complaints I'll upload this as it is.

Rebalancing the bobs beacons as you did it would work too for me. Completely dropping what I did for Seablock specifically. Otherwise you run by default into the oddity of of having both beacons active: https://i.imgur.com/6dabE3K.png

As for balance of that: I would keep all three of bobs beacons at 8 slots. Otherwise the only upgrade you get from higher tiers is reach and needing less modules. You can also be a bit more bold with the costs in terms of power and circuits. My times 10 is maybe too much but times 5 is easily doable. Keep in mind that usually endgame builds can look like this in Seablock: https://i.imgur.com/96uLgim.png Bobs gets even crazier as the modules are lot more powerful.

One error I immediately ran into when disabling your MK2 and MK3 beacons was those statements in data.lua not being wrapped properly like so:

if settings.startup["wret-overload-enable-beaconmk2"].value == true then
  data.raw["beacon"]["beacon2"].icons = data.raw["item"]["beacon2-item"].icons
end

if settings.startup["wret-overload-enable-beaconmk3"].value == true then
  data.raw["beacon"]["beacon3"].icons = data.raw["item"]["beacon3-item"].icons
end

ah, yeah, that would indeed cause issues. I moved those two lines to better spots in the entity.lua file.
changed the big beacons to be 5x cost instead of 10x, and the bobs beacons now have 8 modules slots each, but still have the boosted transmission efficiency. I kind of want to reduce the range on the bob's beacons, and increase their module slots more, the make them more of a close-range but high power option compared to the wide area of the larger beacons.
also I changed the default setting to remove bob's beacons, but it only removes them from the tech, so if you have them unlocked already, then nothing happens. what do you think of those changes?

Sounds like a plan. Have the Bobs beacons go in a similar direction as the singularity beacon from K2?

It all probably needs to see some more actual game play testing and maybe not just from me. So maybe just add the changes and wait for feedback.

newest update has all the stuff in it.
Hopefully didn't break anything...