A welcome surprise! The traditional end-of-year OS4 update has taken a few years off, but I’m glad to see it back, hopefully with more to come.
This looks to be mostly an under-the-hood update. Not much visible from the user perspective. From the release notes it looks like a lot of P96/CGX calls have been migrated over to graphics.library. That sounds like important work; RTG was always implemented as sort of a kludge, so merging RTG into the native graphics functions feels like a step toward de-kludgeifying it. Well done.
One thing to note for Enhancer Software users, now that there’s some development activity on the official OS4, there are some conflicts with AEON replacement components. In particular, AmiDVD and PartitionWizard are completely nonfunctional and will need to be updated. AEON’s Format froze on me. I haven’t decided yet which versions of other duplicated tools I want to keep, so make sure to do a backup before installing.
Not sure who the individual developers are who worked on this, but thanks!