Thank you for everyone who replied.
It seems there is no straight forward approach. Simple "force drums to midi" (turns it yellow) but choosing "Custom Midi style for this track" does something absurd. I can hear midi drums, but when changing these drums to something else (Choose from presets), it changes the name of drums in the mixer, but beat remains the same. Yes, I regenerated. And even if it worked, it seems those presets are only a fraction of midi drums available within MIDI styles.

Stylemaker works with some amount of success, but it is very awkward.

With so many MIDI styles in BIAB I was almost certain there is an easy way to do this. Similar to picking RT/RD. I guess I was wrong. Ideally, there should be a unified track picker....
RT, RD, MIDI and Loops... with previews.

I guess a wishlist item.