I've got one
My SIB is on the (very) heavy side. With transom wheels alone, the nose weight was very high, so I figured for locations with a big distance between trailer and water I could put a C-tug under the bow to make a 4 wheeler.
The C-Tug works very well for this - the pads sit nicely either side of the inflatable keel. The supplied straps were too short and quite lightweight, so I bought some 50mm webbing and buckles off ebay. The strap needs to be tight to stop the C-Tug 'falling over' - I have a couple of handles on my tubes that the webbing slots through nicely.
I would think with an airfloor SIB it might be a problem as all the weight of the SIB will be on two small contact patches and you won't have the stiffness of a solid floor, but it may be ok if you put the C-Tug near the transom.
You can take the wheels off the 'chassis' in a few seconds, and less than 5 minutes to dismantle completely.
Shame you aren't a bit nearer or you could try mine - if you are interested I can take a few pics at the weekend.