Not jig related, but brake
Flat table should be fine for the prepunched stuff.
However, since you are nearing the elevator step, I would go a bit further than the plans in regards to the home made brake for bending the elevator skins. I used a pair of very straight 2 x boards and hinges per directions. I was not at all happy with the elevators. They each have a slight bow in the trailing edge. My local RV'ers say "build on" but this bugs the heck out of me.
Anyway, when doing the ailerons, I got a pair of dead straight shelving boards and a 6 foot piano hinge form the aviation section of Home Depot. It works a lot better at making straight bends.
I swear, if my elevators don't rig up perfect, I'll order a new set and do them again over a weekend.