[Rockter]

Guil...

Your third paragraph?... are you back to the argument that traveller angle per se can change the heel?

The traveller tension is certainly helping pulling the boom down, but the other end of the traveller is pulling the deck up. Net effect on the boat is zero.

You can fix the boom any way you wish.... you will never change the heel of the boat with that traveller, at any angle, at any tension, unless you change the sail trim.

Never.

Isaac Newton governs that one, not Lewmar.

If your argument is extended, you will be able to jack the boat into the sky by tensioning the mainsail halyard. In reality, all you will do is compress the mast, as the mast gives the compressive reaction to your halyard tension action, both within the structure, and both changing nothing but internal stresses. The forces within the ship are still balanced, and gravity, and Archimedes, simply ignore your halyard tension, whatever it be.