Okay, so I did end up finding a solution (immediately after posting). If you go through Piped, they added an option to filter for "shorts" or "videos".
This is not an aswer to your original question, but if you want to interact with youtube servers less, try OpenRSS. They have youtube feeds that are better than youtube feeds, at least they don't track you.
I don't know if they have a filter to show only videos (as in, not shorts), but it's possible that they do, their feeds are pretty good IMHO.