I'm glad you've enjoyed!
On the topic of buffs, it is a tricky one. There is a very wide variety between ones that stack, ones that are permanent, ones that stack in duration, etc etc. Currently, the only things that stack in intensity are ones that say 'per stack' after the stat. I know that isn't super obvious on the ones that don't do that (as it doesn't say anything like 'not per stack'), but it's hard to find a place in the UI for such a message.
I will look into ways to make this clearer however. Cant say when I will have a solution though.