Most of the songs I do are not just beats, but basically backing tracks with drums and bass. To minimize the interaction, and thus train-wreck style mistakes, you have to get creative with how you choose the loop.
I have posted 30-40 “with bass” songs, I think, and I have about 70 more in various stages of completion. Many of them are completely done except for the dreaded “500 note limit”. I wrote a program to analyze midi files, and found that for many of those files, the real notes are well under the 500 note limit, and that it’s zero velocity notes that are putting me over.
So, the song I just posted - Tommy James Draggin the Line - was one that had that exact issue. So I figured out a way to convert all the zero note-ons to note-offs, which the BB doesn’t count. The song seems to play just fine! The nature of the continuing bass means it doesn’t really need the note offs.
Side note: just deleting the zero velocity ones made Reapers display freak out, I suppose thinking that every note continued forever! Replacing with note-offs made it look better.