whazoo,
Wow - 4 crossbars... that's not going anywhere!
Where does the canoe make contact? Is it only on the front and rear crossbar saddles or is it stabilized by something behind the AC? Mine doesn't have as much rocker so it wouldn't clear the AC. I might have to remove the yoke as Kayteg1 did.
I've used nothing but Yakima for the past 25 years, but mounting on a camper roof has a new set of challenges, so I'm looking at all options. Still, I like the Yakima tracks because they attach over a very long span. Is that what you use, or are your towers fixed directly to the roof?
I'm not familiar with the slide out bar (although I can guess how it works). What is the advantage over tipping it off the rear?