I can assure you that users complain when the GUIs of DAWs start to run below 30fps, and really the expectation these days is that "performant" GUIs run at 60fps.
You and the OP are just assuming it can't do whatever it is at "30fps"... if you're right, it will only take ten minutes if it's so bad, or an hour or two if it's subtle, to actually confirm whatever the worst thing is.
The "extra frame" I was thinking of is graphics pipeline latency, not redraw time.
That said, I'd argue that even latency is still a concern for things like meters. If they are noticeably out of sync with what you hear then users will again complain.