Hey!
Thanks for bringing this up, I think what you suggest would be a great feature although I’m not sure how easy this would be to implement. Still, I’ll put it through to the engineers and see what they think.
In the meantime though have you perhaps considered resetting to a lower level? I reset my level from 35 to 15 after a 3 year hiatus and found it to be a much nicer experience to breeze through some levels I was semi-familiar with rather than get frustrated over a huge review pile.
If you don’t want to reset, you could always use this script [Userscript] Burn Manager (Review / Resurrect / Retire)