So I went down the list of PeerTube clients in F-Droid, and the only two that let me pick my instance / login are TubeLab and P2Play. They look nice but there's a problem: they don't understand login with 2FA, and I don't really want to drop 2FA as I always use the extra security whenever it's available.
Any other Android client you're aware of that would work for me?
In the meantime, I'll open a feature request for those two apps.
EDIT:
Uuh nevermind, I answered my own question: when I went to open an issue with TubeLab, the repo says it's now part of FediLab - which, inconveniently, doesn't come up when you search for PeerTube in F-Droid.
I installed FediLab, and lo and behold... 2FA!
And with that, voila: I'm logged in:
Brilliant!
In your opinion, how good is the viewing experience of Peertube videos on FediLab?
It seems fine. The player's interface is very comparable to NewPipe's. It goes fullscreen when you rotate the phone in landscape mode. It starts quickly, it doesn't stutter. No complaints.
I haven't used it very much yet though. Maybe I'll be hit by a really annoying bug I haven't bumped into yet. But so far so good.
EDIT: mind you, I just wanted to be able to comment on videos logged in. If the player turns out to be crap, I can always fall back on NewPipe: it plays PeerTube too, just not logged in.