Cylinder glazing and wet stacking are real issues. I'm not sure that they would be in Texas unless the vehicle just sits and idles all day long. I personally warm up my vehicles long enough to clear the snow off of them or if it is less the -20F, maybe 5 minutes, whichever is longer. I then take it easy until the vehicle comes up to temperature. I personally think long warm-ups kill DPFs and EGRs.
On cool down, the 3- 5 minutes that Ford recommends is like sitting at a traffic light; I cannot imagine cylinder glazing in a 3-minute cool down idle. Additionally, during cool down, you are trying to slow the turbo down and get heat out of it, not load it up.
The old Ford 7.3 and 6.0 had Auxiliary Idle Controllers available; additionally, the 7.3L had an exhaust backpressure valve that shut when the engine was considered to be cold. They removed the EBPV with the introduction of the 6.0 and removed the AIC with the introduction of the 6.7L, I believe. Even without the AIC, my E-350 will slowly come up to 1100 rpm when cold.
These days, they have more sophisticated ways to keep the engine loaded up. I can enable a high idle (1200 rpm) in my 6.6L Duramax but it only is active if it's below freezing and only if the coolant is below 150 deg F. What GM does instead is to pulse the torque converter to load up the engine and simultaneously warm up the transmission. I am guessing Ford does something similar, plus they have radator and I/C shuters.
On the 6.6L Duramax, you can get a separate higher idle kit, but that defeats the torque converter logic, so I'm not sure it makes the engine any warmer. That switch is used more for PTOs or high electrical loads, like an idling ambulance. I only use the AIC on my E-350 when jump starting another car or when using the winch. I don't have the aux switch in my Duramax, so I have to jump start someone with that vehicle, I stick my ice scraper between the throttle and the seat base and power the seat forward until I hit the desired rpm. This is a common trick for expediters who run Sprinter vans.(they use sawed off broom handles).
There are no current MY Ford high idle switches that I know of, even in the superduties. Some guys go aftermarket or custom-make the parts. If you decide to go that route on your F-150, I think you would be the first.
btw, I see my little flag shows Germany. Don't know how to change that; I am only here on business. The only 1/2 ton domestics I see on this side of the pond are Rams, due to the collaboration with Fiat.
