It probably makes sense to allow to press undo on current move single time only. Allow to ask undo again only if move number is bigger than move on which they asked for undo previous time. Purpose of undo is fixing misclick, not time travel.
Disagree. Firstly ‘time travel’ as you put it was possible before this enhancement to allow undo request on your move, it just required twice as many clicks and both players asking.
Secondly the purpose of undo is not only for misclicks, though many people, myself included, limit it to that. It can also be for mistakes or trying something different in a friendly/teaching game.