Creating and building a slide out is just part of the deal, do not forget the issue of sealing up, both when in and in the out position. Having had service done at HWH in Moscow Iowa, never an issue with the slide, the leveling & air leaks was the reason for the visit. There is more it than just moving in / out.
My setup uses the air seal, like a bicycle inner tube around the entire slide, uses air pressure to seal, works great, no snags, no leaks, just does nice.
Seems the seal type that uses the over lapping flange with a rubber gasket have issues with leaks etc.
Good luck
Dave M