[Omatako]

Just a couple of points:

Try have hardware that won't chafe the sails because you don't want to loosen the leeward lines too much and that generally means they will be against the sail. Little pulleys will probably feel better to work with but stainless eyes present less chafe.

I always put the boat head to wind when hoisting the main and the only time the lazy jacks interfere with the battens is if there is a solid blow and the leech flaps around a bit.

Construct the lazy jacks so that the general line of the back lines kind of follows the shape of the leech and about two feet in. Use three triangles to achieve this if you must. The further down the boom you can support the bunt of the sail, the better.

The leeward lines should never interfere with the boom when running off the wind (FrankLanger) because they obviously move with the boom. If they tend to go a little tighter, loosen them.

And the comment (I think Jeff?) that jackstays are not so great for single handers, the first pair I fitted for single handing after years of sailing without them had me wondering why I hadn't done this years ago. I'd never sail without them again.