man that sounds complicated, climbing over the cab!
I have a crew cab long wheelbase truck and I have yet to get my feet wet launching. If I am by myself with my big boat(16x48 jon with a 50hp) I attach the rope to it. I keep a rope tied to the back roller of the trailer all the time and have it strung up to the front. if I fish by myself I hook the rope to the front of the boat, back it into the water with enough force to get the boat floating away from the trailer, then **gently** drive forward to pull the boat to the bank. easy cheesy lemon squeezy.
btw, when you load the boat back up you dont need the trailer as far in the water as you do launching.