I have been using BitPerfect 3.1.1 with the latest version of OS X, “macOS Sierra”. It comes with iTunes 18.104.22.168 as part of the installation.
The results are a bit of a mixed bag. Functionally, BitPerfect seems to be working fine. I haven’t come across any unusual behaviour yet. However, I notice that the Console App has changed significantly with Sierra, and it appears that it is not displaying most of BitPerfect’s diagnostic messages. This is going to make it very difficult for diagnostic purposes. For that reason, I recommend that BitPerfect users hold off from making this update for the time being, unless they have other, more pressing needs to do so. We will dig deeper into this issue and report our findings in due course.
I also need to spend some time trying out the AirPlay subsystem under Sierra, and I haven’t been able to get around to that yet, so AirPlay users might want to avoid the update for the time being unless they are feeling particularly adventurous. AirPlay users who are still on Yosemite in particular should stay where they are. Yosemite is notably stable with AirPlay. El Capitan is not, and Sierra might not be any better.