1. Consider a modification on the shock cord configuration: put two small blocks, for example under the front beam, close to each hull. Instead of going side to side under the tramp, go to the block on the opposite corner, then to the other block and then to the grommet at the other side. This way you have more than 3 times the original length. This way, when you go out on the trap, the shock cord will extend by a much lower percentage of its full length. So the tension will be much more constant and you avoid having the traps loose when unused and too tight when you are aft and out on the trap. For the front trap, you can do the same with small blocks inside the from beam.
2. Ditto