About to enter the painful levels... searching for advice on how to handle the pain

It will be less painful if you spread your lessons throughout a level rather than doing all the lessons immediately when you level up. I recommend using my Lesson Filter script to do roughly the same number of lessons each day. It will let you still learn a mix of radicals, kanji, and vocab every day, but you’ll be able to choose how much of each to control your level up time.

Using the script, if you do something like “blank” for radicals (to do them all right away), 7 for kanji, and 13 for vocab, you should still level up close to max time. But then you’ll only have to do 20 lessons a day (except the first day), which will also keep your reviews coming in a balanced way as well (this is very important). And obviously you’d be able to tweak the numbers if you want to change your pace later on.