So I'm not too concerned with the shine of my car. I'm more interested in protecting the paint and clear coat.
Would I get a better application if I kept the WDGS 3.0 on for 3-4 hours before wiping off with microfiber cloth?
And is it safe to use on plastic and rubber trim, and headlights?
Yeah, maybe safe to use as such to let sit so long, if you're in a dust free, temp controlled condition, like a good garage.
Many years ago, the old timers I knew used to apply some carnauba wax, Simoniz, and the like, then drive around the city all day in blazing summer sun, then remove many hours later.
This old wife's tale was a joke IMO, all the vehicle then did was collect tons of dirts, dusts, and various other cruds just to be ground into the paint.
I'd advise to let the the Sealant sit as short a time as possible per following said instructions of the said product. Dependent upon temps, and humidity, yes, a sealant might take a little longer than a 1/2 hour to fully dry, and initially cure. Rely on the swipe test to be your guide. If it looks good, then go for it. If some difficulty of removal with an MF Towel is still encountered, wait another 10-15 minutes, and try again.
Use for on hard plastics, like headlights, taillights, other light lenses, yes, no problem, as for bumper pads, semi-matte, or textured trim, I'll say no. Regardless of claims said, or not said, I think it wise to avoid such wipe on wipe off sealants on such trim, and to use a dedicated trim product instead.