Paolo, I take it that what you want is for your Qobuz purchases to be automatically added into your library, instead of your having to add them manually, as you do now?
The issue that Paul is highlighting is that now anything that is noted in the Qobuz Purchased Albums list is added a second time into the library (as a streaming copy) by the sync process. That’s needless duplication, as we see it.
Getting back to the automatic adding of purchases into your library, it can be done today, by telling the Qobuz desktop app to download purchases directly into your library, but frankly I wouldn’t recommend it.
The reason is that the download is a relatively slow process, so Roon sees the album gradually appear, and tries to make sense of what it’s seeing. The identification process often breaks as a result.
Best practice is to download to a staging area outside of your library, and once complete manually copy (yes, sorry, still manually) the albums into your library. That, or stop your Core whilst downloading directly into your library is taking place.