Yea thanks for the description, helped a bit.
I somewhat had the same problem with my first summer set up.
I had a pretty big starter that i made out of wood and covered it with turf, the problem was when i got to the bottom, the transition btwn the starter and jump was too intense. Making it less intense did help a bit but i definitely understand your frustration.
Sure a bungee would help, but do u rlly feel like pulling it back every time u want to hit the rail? I think u should try different things with the starter.. make the slope longer and not as steep? build a transition between the slope and jump so it flows better.
IF you can upload picts and i'm sure someone on here will have a great idea that will help..
Do you not have snow? turf isnt the best.. obviously on snow ull get more speed with the starter. Did u put soap on the turf? it'll make it faster