Summary of: https://bugs.winehq.org/show_bug.cgi?id=58552#c42
Windows versions of various audio apps handle VSTs better than Linux versions.
This seems further prove that this merge request is valid despite bug reports against it.
The more I review the more it seems this merge fixed bugs that made buggy code run in a less obviously buggy way.
Thus it seems this merge may have helped expose fixes needed by Wine dependent VST projects.
Yabridge fixes seem mostly fulfilled per new-wine10-embedding branch testing for vanilla-wine. But yabridge new-wine10-embedding still is not merged with upstream yet because of other reported issues caused by this merge.
I will suggest to all reporters to test Windows versions of audio apps if available to confirm VST handling is improved. If most apps report improvements then it may suggest a common Windows lib is taking care of the lower level window handling details that so far have been difficult to replicate on Linux.
With Windows versions proven to improve VST handling, Windows vs Linux build details around VST handling may reveals whatever Windows component provides the consistency across Windows version to be replicated for Linux builds.
If Wine is able to handle VST natively then it may eliminate the need for yabridge translation of vst.dll to vst.so. LMMS already ingests VST DLLs directly and may already be on the right track for VST DLL handling directly through Wine.