One of the biggest issues I see is that if the cuff isn't perfectly
aligned on the wing, the wheel will try to track sideways and cock the
cuff risking wing damage. *Further, it's a big chunk of "stuff" that
takes up space in the trailer or retrieve vehicle.

My first thought is that there are already wing cuffs used as wing
supports in the trailer. *One of these might serve a second purpose as
a wing cuff for the tow out gear if I made it a little wider and added
attach points for a wheel. *This would eliminate the need to find
extra space for it.

My second thought is to use a castering wheel instead of a fixed one.
This would prevent lateral and twisting forces from being transferred
to the wing. *Even if the wing cuff wasn't perfectly aligned, it
wouldn't matter. *The wheel/fork/steering head from a child's bicycle
might be adapted. * I'm thinking that the typical ~20" wheel is much
larger than it needs to be.

Further thoughts about wheels leads me to think a bicycle tire is
designed for traction which isn't really needed in a wing wheel. *In
fact, it would probably be better if it would slide sideways more
easily than a rubber tire. *Pneumatic tires also can go flat. *Maybe a
solid plastic wheel from some other source would be better.

Any thoughts?

Study the Sparrowhawk wing wheel. It is a beautiful exercise in
minimalism. The cuff is somewhat traditional (although would only fit
a 'normal' sailplane's tailplane...), but rather than a fork it uses a
thick and somewhat flexible fiberglass bow with 2 rollerbade wheels
and indeed casters. It is really light (obviously, it was designed by
Greg Cole!) While I myself would like bigger wheels, it is a very
elegant solution with castering the fiberglass bow.

I am making a new one for my ship, but more traditionally constructed.
A hinged (well fit...) fiberglass cuff and a bike fork for a 20"
wheel. My fork will be easily removable though, as it will be attached
via a gooseneck (the part of a bike that attaches the handlebars to
the forks). I am a bike fan with a BMX background so chose 'cool' bmx
parts (FMF fork, Spin wheel...ebay). My 20" bike wheel (oversize for
smooth fields, perfect for rough ones with badger holes etc) is a
sylish composite 3 spoke jobbie that looks really cool, and your right
traction is not necessary. I myself wouldn't use less than a 16" bike
wheel (Cobra wing wheels are 16") since I do visit fields with sizable
badger/chuckholes (probably prairie dog holes for you!) I use a Tioga
Pool Comp tire (a fully slick tread) and have a kevlar tire liner. If
I run into problems with repeated flats (my field is a goathead
factory...) I will pay the few extra bucks to have the tube expandy-
urethane foam-filled for a permanent solution. I like the shock
absorption that pneumatic/foam-filled wheels provide myself, and the
larger the diameter of the wheel the lower the rolling resistance is
over obstacles. My wheel attaches via a quick release skewer so is
very easily removed. The fork also easily removes if I really need to
break it down.

I chose not to make mine quite as light as possible though, as I like
my wheeled wing to stay on the ground. I may even make a provision on
it to accommodate a 5-10# weight for breezy days because it is lighter
than average.

-Paul