There are two recent topics in this forum also related to "fifth wheel" trailers and truck compatibility. Even the parts not dealing specifically with the Scamp or Frontier explore some of the issues and options, so I think they're worth reading. There are probably earlier ones to be found, too.
bigfoot 5th wheel, weight?
5er towing question, Can I do it?
One of the details that comes up in these discussions is that "short box" isn't very specific, because there are all sorts of lengths - even in the same brand - and it's not the length of the box that matters: it's the distance from the back of the cab to the hitch position, which ideally is no further back than the axle
. It would be nice to have the cab-to-axle distance for all the trucks people are considering (for instance, Paul's Tacoma SR5 is 36") and the required clearance for each trailer.
Lacking any more specific measurement, it looks like the Scamp 19'
coupler is ahead of the front of the body so it could be turned a full 90 degrees with a clearance of half the trailer width, or about 40".
The S-10 in that photo from Roger has about the shortest cab-to-axle space in production, so either the Scamp is limited in turning angle, or the hitch is behind the axle
(as Benny suggested in another topic), or the coupler is extended forward, or perhaps some compromise of two or more of these options. Looks promising for the Frontier...