So I've been continuing to play this in the background, more days than not, ever since it came out. I have now officially played all 8001 note charts in the game - that's 500+plus songs each on easy, normal, and hard, plus about half again that have Supreme charts.
I've definitely gotten a *lot* better through continuous play, even without actually practicing individual charts at all, basically sight-reading everything. Early on I really struggled with 8-10 star ranked songs, now 10-12 stars are my relaxation warmup and cool-down. Granted for Supreme charts I started playing with a team that's entirely defense and healing focussed so I can miss a *lot* and still make it through, but ranks where I used to barely scrape through are now ones I can usually make As and even Ss on. Now, up at rank 14+ I'm still barely holding on and getting Bs and mostly Cs. Mostly.
I've actually *beaten* 8000 charts. Because I managed to pass with a C on every other 15 and 16 chart, but the damn FFTAC mix of Big Bridge on Supreme isn't really a 16... it's massively harder than the other 16s, seems like... 18? 20? I'm honestly not sure how it's humanly possible. I tried turning on "simple" mode with no arrows and actually did *worse*. I end up in anti-grooves on the ultra-fast runs where each press registers as "Bad" on a note that hasn't quite happened yet, because the previous note that's actually closer in time had already registered Bad from an earlier press.
So... not thrilled to leave it hanging at one chart from full completion but that's where that's at. Meanwhile I need to raise up some character with Graviga and implement the strat for Yiazmat, which is the only story quest I haven't crushed at this point.