Go for it now. You might find it useful, you might not, you won’t know until you try.
Just expect to be doing a lot of look ups. Some people have no problems with this, while some people do. If you’re finding all the lookups too tiring/cumbersome, park Satori reader for a bit. Study more grammar and keep going with WK and try again in few months time once you have a bigger grasp of the language. If you find you don’t mind all the lookups, then now is the time you should jump into it.
I get there’s always a hesitation of when the best time to immerse is, and there’s a million different opinions on it too.
The thing to remember is that it’s always going to be difficult to begin with, even if you’ve got to level 60 and finished all N1 grammar and have 10k vocab words under your belt. If you’re not actually reading then it’s gonna be just as hard as someone level 20 with N4 grammar and 2k vocab words. At no point is there a line where it’s going to be easy to just begin reading, it’s a skill in itself. (this goes for speaking and listening too)
I’d just dip in now, if it’s too overwhelming you can just keep dipping your toes in further in the future as your confidence grows. Only you really know when the right time, but you’ll never discover that until you try.
The waiting to learn grammar advice is pretty terrible, imo
EDIT: I just reread and noticed you mentioned manga kicked your butt, I’d therefor have some expectation of Satori kicking your butt too.
The advantage that Satori has is WK integration (hides furigana on kanji you know), and instant look ups, plus they’re more light novel style so the grammar and vocab is going to be more ‘dictionary’ than the ‘slangish’ stuff you get in manga (depending on what manga you were reading of course).
The biggest barrier to entry is actually enjoying the content, you’ll find yourself willing to put up with more faff if it’s a story you actually want to read. I never found anything I’d want to read on Satori so have not used it, but it’s a really powerful tool.