I’ve been on this cadence for a while myself, with similar results. I do my reviews whenever they come up, but only 10 lessons a day, and then a bonus 10 when I level up. I’m even thinking of slowing that down a bit by skipping weekend lessons or not doing the 10 bonus ups leveling.
I think it’s important to do all of your reviews asap. If it is starting to become unmanageable, either stop or slow down in taking lessons to regulate your speed. And realize that after adjusting your speed of taking new lessons, it still take a while for your review count to catch up and follow suit.
After reading any threads here, I think that burnout and/or falling way behind on reviews are very common. Since I want to succumb to neither, I always try and lower my lesson level before either of those has a chance to happen.
Also, if you haven’t already, I’d strongly suggest getting a phone app to do your reviews. That way you can do them when waiting for a bus, in the line at the grocery, or at a fancy dinner with your significant other. Yes, you heard me. “Sorry, babe, I need to use the restroom. I’ll be right back…”