How do I greatly reduce or even disable tax inefficiency for 4.2?

[Fumblerful]

Playing a mod with 4.2.  Money is pretty scarce in this mod as productive enterprises barely give any.  I have to rely on my fiefs, which are numerous.  I am currently suffering around 60-75% tax inefficiency.  I tried to do the tweak manually but could not identify the proper value to change.  I know a centralized kingdom reduces this value but it is so high it will not help greatly.  Can I change the max fiefs held before this kicks in?  Can I change the multiplier so it adds far more slowly?

Thanks.

 

[Somebody]

The math is in script_cf_dplmc_calculate_tax_inefficiency. You can also cheat a bit and change the game's campaign difficulty right before the budget report.

 

[Fumblerful]

The math is in script_cf_dplmc_calculate_tax_inefficiency. You can also cheat a bit and change the game's campaign difficulty right before the budget report.

Where do I find that?  Also, how do I read the information.  I found describe_tax_rate_to_s in scripts.txt, but that is all.