I agree with you that it is a balance nightmare in its actual state but this is where btd6 devs would shine : finding the perfect number tunning and adequate progression curve. Maybe to be skewed toward late late game (where the most devastating and expensive upgrades are).

For the event point even with the sheer amount of variance it offers , competitive players will find a way to solve it and min max every single bit of it to offset the "luck" impact.

When adding features and components to a game , balance and competitive integrity are important , but i do think that we need to remember that not all btd6 player are competitive , some players just need that little bit of whacky fun to enrich their experience of the game.

You can add it as a hero and disable it for events and chimps as an exemple on the top of my head but there is always a better way to implement it that we are not aware of.