Who thinks they entirely understand the interplay between promotions, promotion handlers, rules, and actions?

Aha! Good poll. The system is one that's so flexible, it's a big benefit of Solidus over other platforms, but it's definitely not easy to understand.

I'm thinking of some refactorings but first want to know whether it also breaks other people's brains

It's clear here but for the details I need to look at the source code

same for me, between 1 and 2 : it's kinda ok globaly but when I need to make a new rule / action, I have to check some code again :)

If you are doing a major refactoring on promotions, I have few pain points regarding them. Let me know if you are interested to hear it

Yes, the promo system is great but there are some weirdnesses to be sure.

@loic I'm definitely interested