Clarification?
Do you mean a "Hunter Arch", which spans their cockpit, or are you referring to a traveler over the sliding hatch? The former would be unworkable, as there is insufficient boom height. The latter has been proposed using a Harken traveller riser, but these are very pricey systems to buy. It might be possible to build your own riser and cross piece, than mount a standard traveler, but you are changing the physics by moving the mid boom sheeting forward. You would have to increase the purchase I suspect to compensate for the shortened arm. I believe I have seen a picture of this being done successfuly though. One drawback is that a dodger could not be added.Don