Check with Sherpa for a rack. Solid rack and all adjustable bars with a good load bearing rating. 300 dynamic and 700 static. Have one on my 2021 and it has been great.
Went the route of Fox coilovers tuned by Accutune for my 2021 along with Icon UCA's. Much better router than changing preload or spacers. Got rid of the brake dive and rides like a dream along with more travel. Set the castor to 3 degrees and it drives straight as an arrow and no twitchy...
My take is that's the limit on the stock rails and crossbars which are pretty weak. I have a Sherpa on my 2021 and it definitely can handle more than that. The bolts and mounting on the 4Runner are pretty stout built.
How does the hybrid work on overpasses/uphills at highway speeds? Does it kick in to keep from having to put your foot into it/bunch of downshifting? Currently have a 2021 ORP towing a trailer with my Kawasaki KRX1000 side by side which is 3500-4000lbs total weight. I have to lock in 4th gear...