I have been playing around with some stuff and my battery is currently at 72% overall, with about 3.9v per cell, or 11.91 total (3s). Is it okay to fully charge now or should I discharge until it is closer to the 3.3v /cell range?
No they don’t.
If you want your lipos to last well and be reliable, land at 3.6v per cell minimum. I use the timer on the TX for that, I start by setting it for 3mins. Then land, check the cell voltage with a battery checker (essential purchase) then put another 2 mins on the timer and fly that.
Usually FT models will fly for 5-10 mins, depending on how hard you fly and temperature. Lipo is affected by air temps, when it’s cold out I take 40% off the timer on my first flight, then check the voltages.
Landing at 3.6v per cell gives you a bit of “reserve fuel” rather than just running onto the voltage limiter in the ESC and potentially crashing because it limits your throttle or pulses it.