Yes, I see this a lot, not just with Qobuz. Comma delimiters, and many others as well. I always replace them with a semi-colon “;”. But I am only recently a streaming (Qobuz) subscriber, so this is the first time I am seeing the problem in this particular context. Roon also is only a recent partner with Qobuz so maybe there is scope for some kind of pre-processing on ingestion.
I don’t really understand your question though. With these Qobuz issues I haven’t personally found myself “replacing” anything. I just delete the concatenated artist string “Marianne Crebassa / Fazil Say” in the album editor. In this example, there are also individual album and primary artist entries of Marianne Crebassa" and “Fazil Say” separately. So the concatenated artists are kind of duplcates in a way.
Whenever I have come across these concatenated artists in the past after uploading to roon I also have just deleted them and filled in any gaps in my tags of the single artist names if necessary. I have not found roon has reverted any of these edits but I do all the editing external to roon with a 3rd party tagger directly in my files. Maybe the experience is different if editing within roon.l I don’t know.