Support for drum breaks is now available for testing in the iOS beta on TestFlight: https://testflight.apple.com/join/s0ijUrAi

Insert the word “Break” in the staff text and the drums will stop with a shot on one until the next double bar line.
This doesn't affect the bass+piano accompaniment which you can still control with N.C.
Using N.C. and Break you can achieve 4 different combinations:
1 - Accompaniment + Drums
2 - Only Accompaniment
3 - Only Drums
4 - Silence

Coming in the next Mac beta soon and to Android sometime early in the new year.