I haven't been following this thread closely because my bike doesn't stall. I rode for an hour is pouring rain and slush this weekend with no problems. (Monarch Pass, 11,312 ft, 33 deg)
Some questions and food for thought:
Where does tube #22 go?
Can it be getting water into it?
Some valves like those in that tube set are designed to vent air in both directions but not allow liquid thru. So they let air out as the fuel warms up and expands, and let air in as you use fuel. But the air flow rate is so small that you cannot detect it blowing of sucking on the tube.
So, if water gets up the tube to the valve, as you use fuel, it will try to suck the water thru, but will not be able to, and also will not be able suck air in, resulting in a vacuum in the tank and fuel starvation. Sympton: vacuum sucking sound when you open the fuel filler cap.
Related info. The KTM950Adv had related problems. Removing the canister did not solve them. Opening the tank vent valves (in the gas cap on that bike) did solve the problem. I worked for me.
On the KLR there is a vent tube off the carb that feeds down by the center stand. In a stream crossing it can suck water up and cause problems. The solution is the "T"; a branch that goes up under the seat.
Does this fit?