This feature allows the pressure to be set very accurately. I always check the tire pressure in the trailer tires and the tow vehicle tires before setting out on a long trailering trip. So far I've never had a problem. There seems to be two schools of thought on this. One groups prefers bias tires for trailers because they believe they have better resistance to side wall rollover than radials.
Radials generally cost more than bias-ply tires.
In my facility I sold Dunlop, Michelin, Goodyear, and, over 25 years, a host of other name brand tires. Over the same time I have owned three Whalers and trailers ranging from 17 feet to 25 feet. This doesn't mean you can't find a high quality trailer grade tire, it just means most are made for price. In one emergency situation on wet pavement a violent manuever was carried out with more surefootedness than I could have gotten with the bias tires as their sidewalls wouldn't have given and left the contact patch in place on the wet pavement. They did however give a different feel in trailering as the side walls did give and gave sort of cushy ride to the boat.