I know it's been couple of weeks since DD, but I just got an idea.
imagine this set up:
wasd movement, shift for dash, LMB for attacking and RMB for Alchemy
like, I could move with wasd, but holding RMB would change QWEASD to chemical mixing.
Players would stop to mix, but they would always keep their fingers on same keys, and if they need to dodge then there is always dashing (maybe while holding RMB, players would always dash towards the cursor)
Let me know what you think