Again, thanks for the response. MacBook system info:

OS: 10.15.7
CPU: 2.3 GHz Dual-Core Intel i5
Memory: 8GB 2133MHz LPDDR3
Disc: 250GB Flash Storage.

However, my many years in IT Systems Analysis indicates to me that when dozens of applications are running on a system, and one of them uses 5 times as many resources as any other app, the problem lies in the application, not in the OS.

This morning my battery was at 80% after not being plugged in all night. I started Biab 3 hours ago, haven't even used it or loaded a song, and the battery is now at 28% (and dropping as I write this), and it is consistently using ~17% of the CPU doing nothing.

However, it appears that no one else is experiencing this, which was one of the purposes of this post, so I'll carry on as is. I'll just need to keep it plugged in when using biab.
Thanks.
(PS. Battery went from 29% to 20% during this writing)