Cold air drops,you don't want it starting off on the floor!
I have had the Casita with the front air in a closet,it has been an option for a long time.
I got rid of that one and now have one with a Rooftop unit,no comparison you want the AC up as high as practical.
Search for Fred Simson's AC journey in his Fiberstream
,I think it tells the whole story?
I know it is not as simple or quick to make one that has to be removed all the time but I came up with a quick insert and mount deal that made it all pretty easy.
Sorry I can't find any pics of it quick but I sat in my 4500 in our 100 degree + summers here and with the window unit and the blinds closed I could tolerate things even during the day!
I have also seen ones where the unit was stuck in the window while on the road but this just didn't seem like a good idea to me when it was so easy to take in and out and it was nice when I didn't need it that it was not blocking the view.