The problem is with the design itself. There's no way those 2 motors will ever run at the exact same speed and power output. One always ends up pushing slightly harder. That one takes 80-95% of the load and ends up working almost twice as hard as it's designed to.
Other effect is the slide not going out straight and square once the motor starts dying. that can mean you won't get a good seal and have eventual water damage, or as a worst case, jump the whole thing off the tracks.
Buddy with a 2012 toy hauler has the Schwintek slides. Got stuck about 8" out while he was bringing it in. Dealer said to bring it in and they'll fix. Sure, but how do you bring it there with this obstruction sticking out? Next trip, the big rubber seal came loose on the interstate and was flapping 8 feet behind the slide.
Unless you have some very sophisticated sensors and controller, you cant run 2 electric motors like that and expect it to work right.