Generally, my rule of thumb is as much heat as the material will take and not buckle when under way (ie not idling on the heaters). For most vinyls I use around 50c pre, 45c print. Some are more sensitive and I'll go lower to 45c pre 40 print.
Banner material is tougher, satin tends to take more heat than gloss. Also, get the special order F/O ultraflex so you don't have to do a rewind. If you load face in stuff you'll have to load it backward and you'll always have weird tension issues which f up media comp and force you to lower your heat settings even further as it tends to buckle more with no tension. I'm picky about the banner stuff as I like to run the head low for better quality. So keeping it really flat to avoid head strikes is important.
For the F/O 13oz ultraflex satin I run 37c pre, 32 print.
Also keep in mind that I use Triangle JVS (full solvent inks) on a JV3s (slower) in a climate controlled room. The room is pretty much always at 70-72deg F and 45%-50% humidity.