So player has all these nodes that provide abilities. Each node has a signal that the ability is activated. This is correct. What you do after the signal was your question.
The two options i described were:
#1 don't just connect to one omnibus function. Don't connect them all to a _gave_ability() function. This is what it sounds like you are doing. Instead seperate into seperat smaller functions. Connect ability As signal to functionA(), and abilityB signal to functionB(). Then yiu are not checking all 19 cases everything a signal is called.
#2 if you are using the omnibus function _give_ability(ability), set an input parameter for the signal saying which specific signal was emitted. This can be done by code or the inspector when connecting the signal.
Then on _give_ability(ability) do:
match ability: abilityA: Give ability
It's still open for a other 40 hours.
Go here: https://www.gog.com/en/game/tropico_4 then clock the link that says go to giveaway.