It used to be possible right ? doesnt have to be a strictly youtube focused site either, being able to grab url from other sites are always a plus, only suggest apps that are on fdroid (main repo) .
Also for those who dk and might find useful you can use webtor to get a network stream url from magnet links, tho i wont suggest it as the lag and experience is abysmal and misses important functions like seeding .
yes, the first sentence, i didnt have any problem so idk abt the rest, but i only downloaded one extension that one time then removed it half an hour later, i try to keep my extensions to a minimum, i have three now and two are disabled ofcourse ubo being the one always active