Losing Roon playlist 'connection' after converting FLAC to Apple Lossless

I want my FLAC collection transferred to iTunes (Mojave)/Music (Catalina / iPhone) for using it in my car. These Apple apps (still) do not support FLAC files…

My idea is to convert all my FLACS into Apple Lossless which is easy to do with XLD. Both Roon and Apple support Apple Lossless files. After this both Roon and Apple share the same library. Very fine so far!

The problem is that all my Roon playlist + Tags ‘connections’ will get lost after the conversion (I tried some).

Any ideas how to solve this?