How to transfer FRV ratings into Lightroom without losing edits?

As a new user of FRV I have many folders with .NEF raw files which have been imported into Lightroom Classic (LrC).
Some of the files have been edited and rated with LrC, with edits stored in the LrC catalog (no XMP file writing).
There are many other files in the folder which I want to rate and reject using the significant performance benefits of FRV.

Rejecting with FRV is easy, as I can move them to the rejected folder, delete/move when ready and synchronize in LrC. Nice.
Rating is not so successful for me as yet.
If I update a rating rate in FRV it creates the matching filename.XMP file.
When I open LrC I get the expected MetaData conflict detected.
If I replace the metadata (Read from file) to synchronize a folder or selected files, the LrC ratings are replaced BUT edits/masks are REMOVED.
I get why the ratings may be updated, but not the edits.
I suspect it simply clears and all LrC parameters first, then applies the XMP parameters, which makes this a LrC xmp import issue.
I know that there is a decoration (Exclamation!) on each image in the LrC Filmstrip or Library grid where the files are out of sync.
I can filter for these in the LrC Library, so I know which ones are in conflict - rated in FRV and rated/edited in LrC.
Is there alrteady a strategy for this?