I'm using the 'upcoming tracks' view in the right sidebar all the time, it's great for removing and adding tracks on the fly.
However, I've noticed an issue where MB queues wrong tracks. It's easy to reproduce:
1. Start playing an album
2. Remove one or more tracks from the upcoming tracks panel
3. Add X amount of tracks (doesn't matter if they're from the same album or not)
4. MB will now queue the last X tracks from the album, instead of the ones I wanted.
I've made a short screen recording demonstrating the bug: https://streamable.com/u7bmc
Shuffle mode is unaffected. The bug still persists on a fresh install of MB 3.2 RC1