We are now at v5.71pre16, but the region vs tempo envelope bugs that were worked on in v5.70 are still not fixed:
Regions vs Tempo envelope bugs still remaining in v5.70
Since regions are so buggy, I avoid using them, so there are probably many more bugs that I haven't noticed. Indeed, other users have reported that regions even mess up automation envelopes other than the tempo map:
Duplicating content ruins envelopes
