Is a higher TT GVWR better?

I doubt that weight can be used as any kind of correlative as pertains to trailers, safety-wise. A trailer isn't a car/passenger vehicle, where more weight often yields better protection for passengers.

I'm not even sure what's meant here by "safer"-? A trailer is added bulk/weight to a vehicle; and simple physics dictate that the heavier the trailer, the longer it will take to stop.