Would one of you "in-the-know" comment on why mid-boom sheeting was selected for SCAMP? It would seem that it applies a bending pressure in a place where the sail is not attached and the boom is not supported?

Where are you seeing that? I did a casual search for scamp images and I didn't find any that did not have the main sheet at the end of the boom.

The plans themselves show the sheet originating at a rope traveler along the deck very close to the stern. It then goes through pulleys forward up to the middle of the boom before it comes down to skipper or crew. That is the part that is in the middle of the boom.

Many sailors find that having the fall of the mainsheet issuing from mid-boom makes it more comfortable to continuously make adjustments while facing in a more forward direction. It also often makes it somewhat simpler to cleat and uncleat. The boom needs to be stiff enough to resist the bending forces, and needs to be stiffer for a loose footed sail than for one that is attached along the full length of the boom.

Other sailors prefer having the sheet leading forward from the stern. One advantage of that is that the mainsheet then presents less of an obstacle to other crew members in the cockpit during tacks and jibes.

Anders