First of all it really depends on what brand as not all 0w20s are the same.
But most importantly, the slight difference in viscosity when cold is negligible...your engine won't even know. If anything, the thinner oil at startup will flow better especially in the winter.
Mobil 0w20 synthetic we use that at work in the toyota's that require it. Employee get free oil changes I thought it would be a easy way to run synthetic for free lol
OP lives in florida, 0w20 is a waste.
But if it's free, it's not a huge deal.
I mean if slight change in oil thickness can affect VVTI, then Ford really need to go back to the drawing board redesign the engine.