I don't want to make a new mod or game rule for this, so here is an instruction to change the cost of these decisions to match the vanilla cost. You can change the value to whatever you want.

1. Go to where you installed your game and the mod. It should look similar to this:
   C:\program files (x86)\steam\steamapps\workshop\content\1158310\3343278201
   
2. Open the folder [Common] -> [Decision] -> [81_ect.txt]
   
3. Find the line that says: cost = { ... }
   
4. Replace the entire code block with the code block below

Convert to Feudalism/Clan

Convert to Administration

Forming Duchy

Forming Kingdom

Forming Empire