When the Cat is beached or in storage, you could layout a tarp on each side of the Hobie, fill with sand, then pull the corners up and catch grommets with hook on tie down. Pull tiedown across the hulls and connect to other side. When you are done, dump sand and retrieve tarp.
When the Cat is in the water, tie a series of buckets along each side, and fill with water, and let submerge. There would be no stessful weight on the boat, unless it tries to come out of the water. You could add hundreds of lbs of dead weight for the weight of some plastic buckets. Sort of like a vertical sea anchor. When you are done, dump water out of buckets. This is assuming you have it securily moored or anchored!
When towing, use an equalizer hitch, which could preload the trailer with several times the weight of the boat alone. Obviously you don't need the hitch for the boat weight, but it would make the trailer more stable in an apparent cross wind, or induced head wind of driving down the road at 75 MPH.
What, you say you don't tow at 75 MPH? I know, that depends on whether you are headed out for a fun time of boating, or coming back to work after a short weekend!