Hello.
Since last week, I'm prototyping michael's architecture for further discussion. The architecture is similar to LLVM thin LTO.
#32462 was merged into master and #32429 is almost ready to merge.
I couldn't spend much time last week since I was not feeling well, but it got to be better now.
This week, I'll continue to prototype the architecture and work on merging the remaining LLVM LTO PRs.