At turn 38 in a fresh campaign with the above mentioned adjustments I still get the same error:
"String error: [string/"script/_lib/tabletopcaps.lua/"]:2105:attempt to call method 'faction' (a nil value)"

As such I believe it's an issue with the mod itself, as it's not caused by any modded factions (as non are present in my current playthrough).

That same turn the mod instantly breaks, the icons still show, but for example the point calculating completely breaks, if I try to buy RoRs the cost doesn't increase and if I then remove them it actually removes that unit TTC value from the pool, so you can end up with negative values like -1 and bigger, either way the mod system completely breaks, limits go out of the window.

If you confirm non of the changes and reselect the army, the army values will properly update again, but if the player just doesn't do this (like the AI, who just recruits what it can) it essentially means there mod is no longer in effect.

Therefor the mod works as intended, until the very first lua error, at which point it completely falls apart and is useless.

Do not use until fixed.

I have the same problem, in my case it's with the code '2057' instead of '2105'. According to this stackflow post [stackoverflow.com], it appears to be a LUA error that happens when a new actor doesn't refer to an actual, existing actor (my knowledge about LUA is limited, so don't expect me to explain it further). This is definitely something that's intrinsic to the mod.

It's unfortunate to hear they still haven't fixed those lua errors.