The 190 Roadtreks post 2002 have the best tow ratings of any of the class B camper vans I have found. Most class Bs are rated for 500 pounds of trailer tongue weight and 5,000 pounds or less of trailer weight.
Two keys for your rig if you tow are:
1. Roadtrek ordered base vans sometimes without oversize engine radiators or large transmission coolers - so watch for transmission temperatures - heat kills transmissions.
2. Since your dash gauges do not show transmission temperature most likely, you might want to get a Scan Gauge, which plugs into the under dash OBD port
and program it to show digital transmission temperature which I have found goes up quicker than engine temperature in my Roadtreks.
The SAE standards for tow capacity includes climbing a prolonged up hill incline in Nevada under specified hot conditions while maintaining at least a minimum specified speed and without overheating - so the 4:10 rear probably helps achieve the minimum speed for 16,000 GVWR
BUT my experience suggests your trailering skills, precautions and situational awareness are far more critical to safe operation than the legal ratings - just common sense on this point.
BTW, I LOVE my proportional electric brake controllers (Tekonsha Prodigy II)
14 trailers, multiple Roadtreks, lecturer on towing with a Class B to aviation and RV groups Love our Chevy Roadtreks too of course!