Thank for all of the info!
Can hardware length be a problem? The longer the hardware length is in the assembly for main sheet blocks, doesn't that limit the amount of "sheet in" one can produce? With as inconvenient it is to have a single clevis pin and cotter ring, it would be the shortest length between the traveller and the bottom main sheet block.
New to all of this. Just trying to streamline setup without sacrificing performance. Thanks again!
Short answer is "yes."
For racing, a small, screw-in bow shackle is used at the top of the mainsheet. Smaller the better, and on the new boats, the boom bail is installed higher, so you can just barely get the body of the shackle through. Very low profile.
On the bottom of the main, the stock pin is used, or you can use a fast pin or even a shackle (pin goes through the holes; body goes around the side of the traveler top plate.
Jib tack - use the pin of the shackle through the tack and the forestay adjuster and the bow goes around the front:
Jib clew - better to show than tell:
It's a bit hard to see, but the shackle goes through two holes in the clew plate and the blocks are hung off the side. It's a PITA to put on (three hands), but once on, it's the absolute lowest profile and it works very nicely. (photo is from my '98 before I installed the current stock traveler cars)