Once installed, cvlc works for the self-compiled version, though also it just works fine with, say, vlc -I dummy --fullscreen --loop --no-mouse-events --no-keyboard-events --video-on-top --no-osd --mouse-hide-timeout=1 videos/some.mp4. But . . . it still visibly pauses. Arghh!

Reckoning that maybe I was just running things wrong, I've decided to install the possible-abomination I've compiled.

Running in a terminal session unfortunately doesn't seem to really benefit either very much, but VLC's CPU usage is maaaaybe even lower, and it seems entirely viable and so could bypass the need for even something like openbox (which I'm mostly using to avoid polluting the shell init for testing, but this means it could easily be a systemd service for the production approach).

Okay, actually I wayback machine'd it, which points in turn to https://code.videolan.org/videolan/vlc/-/issues/549 which in turn points to https://code.videolan.org/tguillem/vlc/-/tree/gapless-mr which was set to maybe be merged into VLC 4.0 . . . and maybe it still will be, but 4.0 isn't out yet anyways.

Got back at this, decided to try to run just direct invocations of video players that have hardware decode on the Pi.