Hi!
This is a really good guide! 
I actually just went from a year long absence and 2.200+ piled up reviews on level 19 two months ago to just having leveled up this morning! 
Finally!!!
I achieved this by doing my reviews anytime I could and not caring if they were right or wrong. I didn’t reorder by level, but I used a script to get reading-meaning 1 on 1, since I felt that this was easier on my nerves. And I started to write all the things I got wrong down after a while.
I documented it a bit more here, if anyone is interested:
Thanks for this thread, I’m sure lots of people will find it useful!