Not sure on the Getaway but I can tell you this...A Hobie 16 DOES NOT need to have the shrouds loosened up to lower the mast. Your buddy is crazy.
On the 16, lowering the jib loosens the rig. Unless he has a furling jib. Then it works the same as the Getaway.
The Getaway jib is affixed to the forestay, so rig tension is done by pulling shrouds or forestay tighter. You pretty much have to de-tension a shroud to get the forestay loose (if the rig has proper tension). It is easier to pull the mast to the aft / side to get that done or sheet the main hard to one end of the traveler (watch for wind shifts etc). I prefer the halyard or a trap wire to hold the mast over until a pin is removed and replaced again. Trusting that the wind is not going to increase or shift direction makes the main-sheeting technique risky.