Never had a problem with three Newmars since 98 with a motor in fact never had a slide control problem either.
If you follow the slide spec's by Newmar
everything should be good. More info in QT's 1 & 2.
Now that's not saying people have had problems by over adjusting pots on controllers or if the motor on older MH's is exposed to the road salts when its mounted in same exposed compartment as where the LP tank is.
Newer MH's the motors are in closed compartments, the motors are low torque type and will crush your fingers or anything behind the fascia of slide, slow but sure I always say with Newmar slides.
If you level coach
than place slides out you will not cause stress to slide operations or motors.