So it's the number of assets loaded that cause it and of course whyem would tip it off even with your edits given all the other textures you have... i don't have practically any texture mod so i think i will try your edited version.
it would be interesting to test roughly where this tipping point is i also find it interesting how in your first test with the edited whyem it worked for a few minutes, given your tests would you say the spawning issues are kinda also time based depending how long you play? (also thanks for doing the hassle of editing 2000 files)