You can force the song to a simple arrangement, but that is for the entire song.

One way to achieve what you require would be to apply a different RealDrums / RealTracks to the first 8 bars, and then switch to the RealDrums / RealTracks you want at bar 9 using Bar Settings <F5>, as shown:

Attached Files (Click to download or enlarge) (Only available when you are logged in)
2021-01-18_15-48-21.jpg (50.3 KB, 28 downloads)

BIAB & RB2024 Win.(Audiophile), Sonar Platinum, Cakewalk by Bandlab, Izotope Prod.Bundle, Roland RD-1000, Synthogy Ivory, Kontakt, Focusrite 18i20, KetronSD2, NS40M Monitors, Pioneer Active Monitors, AKG K271 Studio H'phones