I had a brainstorm this morning (maybe a brain fart??) but I thought I'd throw this out there anyway because some seem to want an outside galley (my choice too).
This is what I was thinking and I don't think it would be difficult to pull off.
Seems to me it would save you space because you would be using hard to get to space under the bed anyway. The upper cabinets could be shallow for can goods and other foodstuffs, at 10" you could get quite a bit in there without taking a lot of space from inside the trailer.
With cabinets in the galley pull out for all you larger stuff, pots and pans and such I think this would get you as much if not more room than is in a tradition tear galley.
Using this it opens up the whole front of the trailer for a bath and small counter top or bath and dinette eliminating the need for a set up take down deal.
Also the rear trailer wall becomes an awning when opened to pull out the galley, giving you 5-6' of cover which could have side curtains made for it if you wanted. It would be fairly easy to build as it's nearly all flat and probably could be flat depending on the lower trailer profile.
It needs a little refinement to work out the details.
It was a quick drawing but I think it could work very easily.
I hope this makes sense to someone besides me.
By the way, if ya just think it's a $hitty idea that's fine too, it was just an idea after all.