Well, for one, if you have these files in a dedicated Roon appliance with an attached HD (such as a Nucleus), exporting is a useful and simple way to get those files to your desktop.
Ok, I now understand what you mean by “customizations”. However, I don’t really have much metadata customizations. By and large the most “work” that I do in Roon is to make albums versions of the same, which Roon is not great at recognizing. In particular, TIDAL and Qobuz versions of the same album are often not grouped.
But you see, that was my original question. So answering the wrong question is not really the point. As it stands, if I transcode to FLAC, I will loose all my playlists, plus I will almost surely have to regroup versions of thousands of albums.
I am not sure the suggestion of having duplicate libraries makes any sense. Sorry.
And on the point of being hard to help, well, I am not going to say “thank you great suggestion” when it misses my question and is no help at all.
@dylan already answered your original question. The entirety of what you want to do and accomplish is not possible.
@evand, knowing what you had asked about was not possible, tried to offer you a partial solution to the problem you stated in case that was useful to you. You did not seem to understand the suggestion so I explained it to you using your own words which are “customizations” and “tweaks”. I can only assume your were talking about metadata with those words as “playlists” are playlists.
You could say, “Thanks, but those suggestions don’t solve my problem which is really more about playlists and album groupings”. You could add “Based on @dylan’s response, there is no solution possible for my problem.” Maybe then people would stop making the mistake of trying to help.