Good news: after suffering from issues with python310, I finally managed to find the two required patches
https://www.reddit.com/r/reproduciblebuilds/comments/1573d76/reproducible_python310/
and mcepl (our python packager) sent them towards Factory and SLE.

I also worked with fstrba to make nice progress on xmvn UUIDs
https://bugzilla.opensuse.org/show_bug.cgi?id=1162112

Meanwhile, the fix to ghc-rpm-macros is still waiting to be merged.
https://github.com/opensuse-haskell/ghc-rpm-macros/pull/1

Add to that the doxygen toolchain fix https://build.opensuse.org/request/show/1099185

Once all four fixes above reached Factory, this should fix over half of the remaining issues.


A few other major headaches like mono and javadoc still remain unpatched:
https://github.com/mono/mono/issues/20172
https://bugzilla.opensuse.org/show_bug.cgi?id=1174795