petty issues

What is the aerodynamic (or other) advantage of letting the jib boom pivot on a string fastened about 25% aft of the tack vs using the forestay as a pivot axis like full size sailboats do?

thomas.armstrong

It has nothing to do with aerodynamics.
For upwind sailing, what you describe is best - but this setup makes it possible to go wing-on-wing when running dead downwind.
How? By allowing the jib to balance near the middle, thus needing almost no effort to change sides.

petty issues

Ahh, Interesting! I've never tried that or seen it done. If only one winch for both the main and jib, I imagine the manuver involves quick reactions to abort a full gybe as soon as the main or jib flips over. Does the jib or the main typically flip first?

AEK42

The main usually flips first. It doesn't make any difference if they flip or not, unless you need a starboard tack advantage, racing. an RC boat gybe is not the problem it is with full size boats.