Two features a must in a fifth. Who builds them

Trust this is not hijacking the thread. This is in no way to answer or influence the OP's needs or requirements. I too have always heard that slides are not designed to hold weight when they are in, or slightly extended. Please correct me if I am wrong.

Also, if one has Schwintek mechanisms on slides, it is not advisable to partially extend the slide and then retract it. It must be fully extended before it is retracted to maintain alignment.