It sounds like Debian has enough of a community of users and developers who are motivated to keep accessibility alive. I’d rather build on Debian stable than try and build a franken machine. While the bookworm default version of Orca is as old as bookworm it does also have a back port of the latest version.

Trixie is in freeze now so it’s a good time to test and report bugs so the final release can provide as smooth accessibility experience as the last release.