1- I see a grayish background (macOS mojave), which seems like an unintended change (aka bug).
2- For the sample rate buttons, it feels more intuitive to me that it starts with 44.1k and then goes higher to 48k and 96k, now maybe also add 88.2 and 192k? Those are also pretty common. Then it'd be better to have "Use Callbacks" and "block size" in a new level below or rearrange things differently.
3- As for the release notes, I pointed a couple of issues here:
https://github.com/pure-data/pure-data/commit/740212e66012d35ee14eb0fc3fb9a81841025be7#commitcomment-41393798