I wouldn’t pay much attention to the naming of the level brackets, they really don’t mean much. People just like to categorize things and 10’s are nice round numbers.
As for tips, I would say it took me way too long to realize it’s not ideal to knock out your lessons in a single sitting, because then you’re forcing them to show up in an equally large review batch every single time they’re due. I like to knock out the radicals and kanji immediately, but then slowly chip away at the remaining vocab over the next few days so that there are 0 lessons right around when new terms get unlocked.
Edit:
Also, I would very highly recommend Jitai: Jitai (字体): The font randomizer that fits - #2 by Auroden
It’s a font randomizer that’s way more effective than the one available at greasyfork. It takes a little bit of setup, but IMO is absolutely worth it because it allows you to drill with fonts that are so distorted that you have to identify the individual components of the kanji instead of recalling based off of vague general shape recognition. There have been times where I recognize all of the pieces of a kanji in some crazy font, but still can’t identify it and have to mouse over because I only learned it as a basic overall shape that it no longer resembled.