Keep in mind that support for SMB is technically either available or not, in each so app. I don't believe anything hides SMB from apps, on Debian derivatives, by default. (It seems inconvenient, but, anecdotally, it causes fewer headaches. Access over SMB is different enough from local storage that lying to apps about it causes issues...specifically the kind of issues we see with network shares on Windows.)
SMB is old enough that a huge number of apps support it, but it's still extra code that each app might not include.
For apps that don't support SMB, I sync a folder between Synology and a local drive, using the sync app that Synology provides.