I recommend adding the option to do unlimited reviews. It would be useful sometimes, especially with simple things.
That is for lessons, right? If I have done all the lessons and reviews for now I can’t do more reviews.
I have a situation where I have 0 lessons and 0 reviews. I can’t do more reviews.
It’s for (quick) leech review study for your most failed cards. You can do it anytime and as many times as you want. You should have a list in the deck home page. Otherwise what you are asking for isn’t SRS which sort breaks the cycle. The quick study is meant for after reviews (no before) otherwise you spoil the review. BTW, you can do as many lessons as you want…can lesson an entire deck a day if you want.