The older BD-serial / first-generation devices are not really updated much any longer, if at all. Since this particular critical issue 3.12.7 revision was for those of us who got on 3.12.6, you shouldn’t be affected.
Your beta firmware of 3.n.n has more functionality than the 2.n.n most BD-serials would be stuck on (in stable). I’m not sure there is a viable downgrade path from v3 to v2, so if you’re not experiencing issues, I’d stay put.
If you are experiencing issues, maybe start a thread about those specifically, and/or chat with Bond support directly in the app. They are fairly quick to respond.