Question about weight on topper

I'm looking at a Leer topper for my 2012 Tacoma. I can get factory Thule racks from leer installed. Each rack is rated for 150lbs so 300 total. I'm looking at a roof top tent that weighs 170 and then people add more. Some guys are saying it'll be no biggie and others are saying it'll be too much with two people in a tent. I understand the math, but anyone on here have experience? A second option idea? Anyone?

 

No experience here but FWIW, I believe it's more important to know the weight capacities of the shell. Some have the reinforced roof, which will hold much more weight. Just make sure you get the shell specs from the dealer.