The menus on the F6 are deep and complex. Wading through all the settings is time-consuming, but it's something you should certainly do, maybe on a rainy day. But here are a couple of settings tweaks I've found useful.
One thing I've seen said is that in 32-bit float mode, the record level knobs no longer work. In fact that's not true; the level knobs work the same in integer and float mode, and set the record level as you would expect. The difference in 32-bit float mode is that the level you set with the knobs is just a default; you can tweak it in post, including pulling it down if it's clipped.
The wrinkle here is that the record level knobs, by default, don't work while recording (in either integer or float mode). When you press record, the current record level is locked in, and the knobs become faders. These don't affect the record levels of the individual ("iso") tracks, but they change how those tracks are mixed down to stereo. This affects the headphone levels, line out, and the recorded stereo mixdown ("LR") track, if you use it.
For me, the stereo mixdown isn't something I ever use, and I would rather have the knobs always set the record level. The good news is that you can fix this through the settings. Go to INPUT → Track Knob and select Rec Level (as opposed to Reference Level). Now the knobs will always be record level knobs.
The manual, which you can download from their web site, has a nifty diagram on page 194 which shows the routing of the audio signals. This shows how the record levels work differently to the faders.
Due to the file size limitation of the WAV format (and of SDHC cards, if that's what you're using), your recording will be split into multiple files if it goes over 2GB. This is fine, and it's easy enough to stitch these together in post (just butt the clips together on the timeline). But the big display on the front of the F6 shows you how much time has elapsed in the current clip; i.e. since the last file split. I would prefer to see the time elapsed in the whole recording.
Again, this is easily fixed in the settings. Go to SYSTEM → Settings → Display → Time Display. You want to make sure that Recording is set to Elapsed Time, then set Rec Time Reset to Off.
Of course, if you prefer, you can set Recording to Remaining Time, so you can see how much space is left in your card while recording. I tend not to find this useful, because my card (64GB) is much larger than anything I'll ever record.
There are a lot of things in the menus that might be relevant to you, and I can't cover it all. But here are a few things that caught my eye.
