Re: longer hitch for launching boat
Yep Strap launch... although a decent set of dolly wheels helps. The hard wheel on the adjustable dolly is not built to take those kinds of stresses. Tractor supply or a hardware store will have fixed, or rotating dolly wheels that can hold up to #600 of tongue weight.
Make sure your boat tongue weight is well positive, chock the wheels of the trailer.. unhitch, lower trailer down onto the dolly wheels... rig a strap from the trailer to the tow vehicle (actually do that first before you unhitch)... then slowly take up the slack until the chocks can be removed... Back down.
This procedure requires you to be all lined up first, but it allows you as much extra distance as you like (as long as the strap), to get the boat in... It ALSO requires a very long ramp.
"Rum Line" an S2 7.9 - cheap, fast, trailerable, and paid for.