The script lets you work on the currently-due items without getting flooded by the overdue ones.
I’m in the same boat chipping away at 500 (now 350) reviews from a year ago, and missing 30-50% each time. I do about 10-20 per sitting a few times a day (because I lose focus with anything more) and if there’s nothing waiting for me I “unlock” another little batch of old reviews.