Game developers stick to the rule-of-thumb 16ms (60Hz) update constraint to have updates done before drawing.

Not sure how work can be done on something like KWin without that rule guiding decisions.

In the past I would have aggreed. Nowadays where gaming monitors have freesync/or some nvidia sync mechanism(TM) refresh rates go up to 120hz or even 144hz. So the timespan is even lower to update everything.