The latest 2.1 beta is available here: https://rkb21-updates.next.audio/Rekord%20Buddy%202%20Beta.dmg
2.1 introduces a new way to sync your collection simply by importing from one and exporting to another. This give you total control over what happens during a sync and should make mistakes less likely.
Always remember to keep full backups of all your data when using a beta builds.
Also, betas don’t tend to migrate the database when we make changes to it (in order to speed up new build releases) so be ready to re-import your data into a fresh database when a new build hits.
Once you’ve started using the 2.1 beta, do not go back to using 2.0 as it could confuse the syncing engine in 2.0 (because things would be modified by two different apps).