Lots of people have thought about the 270 on a van. I have had countless discussions.
Main issues are the pivot point needs to be in the far rear corner. Take a measurement, usually 8 ft for the length of the case , from that point and you will end up in the middle of the cargo door. If you have the flip forward triangle then you can get some additional coverage.
If you have a fixed top or stock roof can with a rack to mount to you have a chance.
With a pop top you are relegated to gutter mounting solutions. The eight feet measurement puts the forward end of the awning case way shy of the B Pillar. So, a solution here is to run a piece of Aluminum angle about 10ft long or more across the face of three brackets (and you will probably want four brackets) to provide a mounting plane for the awning case. DEFINITELY an awning w legs as the gutter will not support a legless awning.
As mentioned, the full deployment or none at all is a deal killer for us for any type of awning. The ability to extend whatever we need or whatever space allows means we use thd awning more often. The ability to deploy quickly and retrieve quickly if we are leaving the van or wind kicks up are priceless (or at least $1200 from the pictures sent to me recently)
Do not get me wrong, I love the 270 conceptually but would not find it practical, at least for our applications.
Beastie 3: 2002 7.3 EB Cargo: Agile TTB, CCV Mid Top, Custom Walk Through, Lots of stuff added. BlingMyRig.com