I feel like you also want a mechanism to suggest to users not to do more lessons when more lessons would be nudging their short to medium term review workload over the “review limit” (effectively an automatic equivalent of the “stick below nnn apprentice items” rules many people follow already).
I think there’s definitely an interesting unexplored design space in trying to marry up SRS with more human-centric UI that doesn’t effectively assume a robot user who always does whatever reviews the system requires every day. There was an interesting discussion of that kind of thing in the comments on this thread.
Vacation mode could perhaps usefully be tied in here - that is effectively the user saying “I want a daily review limit of zero”. If you could tell the system in advance “I will want a zero review limit for two weeks starting June 15th” and it would wind down lessons so as to make that as non disruptive as possible that would be neat.
Especially in the zero or very low limit cases it would be nice to give the user credit for having remembered an item having not seen it for the time period they actually didn’t see it for rather than the nominal time-between-srs-levels. That implies a system more like jpdb or anki where all cards get their own adjustable time to next repeat, rather than a fixed “each srs level has this schedule”, though.