Given a lot of it is just repackaging
If it's mostly classes/packages being renamed, could https://github.com/jenkinsci/bytecode-compatibility-transformer/ do the trick then?
A challenge we have is the long tail of lesser used, not well maintained plugins. If we can make old plugin releases continue to work with new versions of core for relatively low effort, that would be beneficial.
Especially in a space where failure of the plugin would make login etc. impossible.