Fun to watch and informative. I also own an Alu-Cab Shadow Awning but I'll be broad when I say that all 270 degree awnings face this issue with shade when the sun is not directly over head. He is correct about that.
I've owned the Rhino Rack Foxwing 270 as well as the Alu-Cab Shadow. At least the with the Alu-Cab, you can leave it deployed and move the vehicle though... no poles necessary.
With both awnings, I've purchased the Wall Kits / Tapered Extensions for this exact reason. Typically, I carry (2) of the sides with me at all time for shade/wind block coverage. It's simply the nature of the beast with these awnings. The sides add an extra few minutes but it's the only solution if you don't feel like moving the truck and the sun is low.
If you can remember to position the truck ahead of time before deploying the awning then this is 95% a non-issue

Also, in terms of the Alu-Cab Awning it's bomb proof. Unless the winds are absolutely crazy I never deploy even a single leg or rope line.
My only gripe with any 270 degree awning is the price... they are pretty darn expensive.