my guess is to make it work it would have to be really long. I guess if you were really short and had really small feet wedges would be fine.
I am not sure I explained myself concept well.
What I would love to see is a wedge style camper be 24-30" higher, looking just like the popups, until it wedges up vs popping up. The area over the cab would then have storage space even when collapsed. Instead of the wedge coming from a narrow (unuseable) point there would be foom for your feet at the end so a shorter bed would not be such an issue.
I would guess there would be some structural details to work out but, think of all the advantages: bedding storage, greater useability as a bed. The extra space could even be as little as 18", also with the extra built in headroom maybe the wedge angle could then be smaller. I can tell just by looking at them a wedge is not for me, but if one was made with the extra height, it would be a game changer.