I can't answer about the trailex trailer, but I have a Getaway on a steel galvanized Genesis trailer and I have no problem rolling it around by myself. When I roll it it up the drive (which has a slight uphill slope) into the garage, there's a 1 inch lip I have to bump it over, and my wife helps me there, but I can get the boat and trailer over the lip by myself with a little momentum.
I do have a folding dolly wheel on the hitch. I have that on my very lightweight canoe trailers too, because it just makes them easier to handle, instead of trying to support the weight of the tongue of the trailers and pull them around. Just remember to fold it up before you start trailering...yes, there's a story there.

If you are trying to beach launch it by hand from the trailer? More of matter of the trailer tires sinking into the sand, I think. I made a beach dolly for about $250. I bought the aluminum tube from OnlineMetals.com, the collets from McMaster-Carr, and the pier wheels from Mill's Fleet Farm.
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