Timing Is Everything
I have the same concern every spring. Basically since my ADCO cover is "breathe-able" and is somewhat loose fitting, it is already dry. I don't want a cover that keeps in moisture. I wait for a sunny, breezy, warm day if possible and remove it before the sun goes down and temps start to drop. Catch it before the evening dew starts. I've never had mildew spots appear with this method.
"If everyday is a break-even day, I'm good with that"
2020 JayFlight SLX 287 BHS, UVW 6,180 lbs
2015 RAM 1500, 8spd, 4x4, 5.7L, TowPak, 3.21 ratio, Fastway e2 2-Point Sway, AirLift 1000, GCWR 13,800lbs
1998 Coleman Redwood Pop-up (sold2020)
2000 Ford F-150 SuperCab (sold2018)