I am assembling the boat with net tied tightly to check height etc. Then I will run it with old rig. If all is well I will run bolt rope tramp on three sides and secure with grommets at one end. So sit on boat and lean against and then sit into tramp and then sit on pipe with foot straps and then trap.
Curved sections are three mm 2X1 and pipe is regularly used for skiffs. But that does not meen they are strong enough and maybe I was too worried about looks and weight.