Thanks Bill for the great info, much appreciated. Your comment about the fuji sprayer just made my wallet feel 600 lighter. Hope this sprayer gets the job done well.
The settings on the pro guns give you a lot of control, but have to set up right, and you need to be able to repeat the settings.
For a starting point, on my gun equipped with the standard #4 cap, the best position for the needle is to back it out (from closed) about 13/16 of a turn. The air valve in the hose coupling goes from 0 (fully closed) to 90 degrees (fully open). I find the best air flow setting is about 50 degrees open from the fully closed position. But what you should do is set the needle at about 13/16 turn open, then adjust the airflow until the atomization just starts and you get a sloppy, splattering fan. Keep opening the air valve until the fan looks healthy with no splattering, but the air valve is still less than fully open. With the minimal spray I suggest here, drying times will be less than 20 minutes per coat and you can leave the canvas vertical the whole time.
If you want to go for broke, that gun will definitely be able to soak the heck out of a canvas on a single pass if you put the pedal to the metal, but be sure the canvas is laying flat or you will get mega-runs. You will get very high gloss on heavy single coats, think about mixing in a little matte if you take that road.
On my gun I closed the needle all the way, then with the edge of a file put a little mark at the 12:00 position, very helpful reference.
Your gun will probably has the ability to adjust the fan size by screwing the cap slightly in and out relative to the paint orifice, using the black plastic threaded collar. Best position is with the cap surface nearest the orifice exactly in the same plane as the orifice. Much different than the Wagner, on the Fuji the cap is spring loaded against the black plastic retaining collar, so don't just automatically tighten the collar all the way in which will give you a smallish fan and inferior atomization.
Remember that dilution is very important. If you wind up with a sand-papery surface you need a much more dilute solution (or you're spraying way too far away from the canvas, for distance reference I use the tips of my thumb and little finger spread as far apart as possible). Syrupy GlamourII out of the bucket would NEVER spray well, you absolutely need for your GII solution to be 45 to 50% water. Clearshield out of the jug is much thinner, but it still needs some dilution, maybe 20 to 30% water.
One thing to watch out for is NEVER let your gun fall over with paint in it. The paint will find its way into the little plastic tube used to pressurize the can, and then glue shut the little plastic one-way valve in the line. If this happens immediately pull the tube off the gun and use your mouth to blow water through the tube in the right direction to clear the valve. BTW you should buy the kit with the spare lines and one-way valves, they come three to a package. If you place the gun down on a ledge with the hose attached, you can just about be sure it's going to fall off. I make a point of never allowing the gun out of my hand when the hose is attached, except to hang it up on a long nail in the wall.
And keep the turbine as far away from the spray as possible, those filters suck a lot of air.
A minor gotcha I have noticed is that the masking tape I use to hold the print down does not soak up paint anywhere near as fast as the canvas. So there is a situation where the canvas feels dry but the tape is still wet enough to generate a drip on the next pass that will find its way onto the canvas. So before starting a pass feel the tape (or backing) above the canvas and if it feels too wet just wipe it with your finger or a towel.
Good luck! I feel the Fuji was a great investment, coating those big canvases has moved from a high stress, much dreaded semi-nightmare to one of the easiest and surest things in my workflow.
