@Trash at **** when a front line unit dies it gets replaced by another front line unit. Breakthrough chance is the chance when a front line unit dies instead of a new front line unit it brings the artillery to the front row. PDX added this feature to the game but currently in vanillia eu4 there is 0 sources of it.

This mod is forked from silvertaped for a mp game and I have no clue how well it works given its almost a year old.

\Program Files (x86)\Steam\steamapps\workshop\content\236850\3105283657\common\defines
you can go to this file path for silvertape changes

buildings were +50% cost
war exhaustion had -morale, -defensiveness, and global monthly devastation

What does "Vanilla breakthrough" mean?

Also could I know what the other values were in Silvertaped/Homebrew? (I assume this is where the mod forks from)