It sounds like you are in that old loop that I call "no-tech-techs" as they just want to walk through things without really getting down to the tech parts!
Did any of those "techs" actually try to look at the drawings to see what they have?
Since there is an almost unlimited number of ways to wire RV, I would think a good tech would not try to remember what is involved on every type! That means most good techs will have to look up some info, not just shoot from the hip and blunder through the job.
This is the 12VDC drawing for your RV:
https://www.winnebago.com/Files/File...ire_159727.pdf
Sheet two top and right side show part of the control info for the slides. Rear slide is about top center, while front slide is shown about half way down on right edge.
Slide power also appears on page six, bottom left.
Several controls and modules are mentioned but not location on these drawings. click these snips for a better view or go direct to the drawings for the complete story?
Best of luck to you as dealing with RV repair techs is a real minefield for finding the bad ones.