self tacking jib roach

[Pieetry]

how much roach can be put into a self tacking jib? is it possible to put some full length battens in it to make it almost over laping?
or is it limated to a simple straight edged triangle?

can the leach go farther astern then the location of the track?
what would be the advantages and disadvantages of this

yes i know the jib will rub against the mast during a tack

im working on designing a small 1-2 person 29er like skiff and im trying to keep the center of pressure as low as possible.

THANKS!
have fun