http://bugs.winehq.org/show_bug.cgi?id=58552
--- Comment #25 from Patrick patrick+winehq.org@laimbock.com --- (In reply to Stian Low from comment #21) [snip]
Therefore it seems for virtual desktop mode the effort should be to make the VST windows all appear within the virtual desktop rather than popups appear outside it and aligned with the improperly displayed VST windows.
Maybe this commit in the yabridge new-wine10-embedding branch could help with that? https://github.com/robbert-vdh/yabridge/commit/2c6c21409c882411f0f26bcc63b64...
(which also needs https://github.com/robbert-vdh/yabridge/commit/02fb140b197f3a31ed1d5ba1233e9... on top of it)