Robert, it depends on what is meant by parallel fold, on Fairey aircraft pre-Firefly
(the monoplane) the main planes swing aft, they do not swivel into the vertical plane
ala the Grumman types. I haveseen pics of Swordfish and Albacore with rockets/small
bombs in place with wings folded, not on Firefly.
The reason is simple physics, if the wings sweep back in plane the loads on the ordnance
mounting points stay the same, the loads shift on an up-and-over fold, but settle down to
a state close to flight position. So provided the wing hinge/spars etc. are strong enough a
straight fold to the rear type could, hypothetically, be parked armed.
With the skewed hinge rotating fold back the load surface, the underside of the wing,
and thus the load on the ordnance lugs is in a vertical position, which completely changes
the stresses. Add in that with the Grumman type the lower surface of the wing is towards
the fuselage you have less room for underwing stores to stay in place. On the Firefly the
lower surface faces out when the wings are folded so space isn't an issue, however, you
still have the problem of the stress on the mounts.
Logan, the Barracuda was designed by a Belgian, so make of that what you will ...