As the original post was about sand , and just my 2 cents , I've never seen the need for a locker , as never lifted a wheel yet , before buying the patrol I had a 2.7 lux towing a jayco Swan , the lux was on skinny steel rims and the camper is on 14 inch x 175 , 18 psi in all tires never had a problem . And that includes indian head on a hot summers day , and with the patrol definitely no hassle or worry in the sand . Drive to conditions momentum is the key not speed
Just my 2 cents worth I've seen rigs with all the bells and whistles down to the belly only to see a soft roader drive right past

Steve