Even though those are the correct controls I tend to think of the < and > as the mnemonics because it makes kind of sense (but those are shift)

That's why they are the keys in fact. Those are the usual shortcuts for frame navigation in some video editors.

And < and > increase and decrease playback speed, for what that's worth

And are placed somewhere completely else on Swedish keyboards but it was an Aha-moment when I realized as a child that the keys ,. was really supposed to be <> for arrows in some games 30+ years ago :-)

mpv controls!

I remember the first time I absentmindedly pressed . or , on YouTube and was shocked that they used MPlayer's keybindings (and implemented such an obscure, but useful, feature). Oddly probably the least copied feature across video platforms, I like it a lot, but nobody else seems to have stolen it. (Can anyone believe that Twitch has gotten away with such a terrible player? I remember people used to send streamers Twitch VODs to review, and every time they paused the video gets greyed out. Twitch never changed this, and now people use YouTube for that.)