[popcornmix]

Is it safe to revert to an older build even though the recent builds have db updates?

Should be fine. Old databases are left behind when they update.
If you run an old build it will use the old database.
An old build will never try to use a newer database than it was designed for, so it can't break your newest database.

But as it's so easy to backup an sdcard (with dd or win32diskimager), then it makes sense to backup first just in case.