BW2
I looked at that Select Suite on the web, and sure enough, they put a patio awning on the slide.
I have no idea whether or not the slide could take it, but it would seem to me the weight isn't the factor, it's the stress of having an 8' awning out there supported by the slide face.
The common Keystone answer is - if they didn't put it on at the factory, they are not responsible for adverse affects as a result of the installation. If the Dealer installs it, the Dealer is responsible. That includes anything from rear hitches to suction cup towel holders
. Not saying Keystone doesn't stand behind thier product - because they DO, more so than others - but it is the safe answer from thier perspective if you ask.