I am really knew to the motorhome world but I think its not what the slide motors " can do " but what is best to protect them. Sure I think they are strong enough to work through some minor binding but why put them through that.
When we looked at ours for the first time, the salesperson did open and close without using the leveling jacks but she did start the engine to operate the hydraulic jacks.
When I open and close, I level first. It just makes sense to level and support the rig before asking the walls to move. Plus Mr. Clemens said to do it that way.....