From what I have read by the experts, in heaving to, the idea is to set everything so the boat sails slowly upwind, won’t tack, won’t fall off downwind, and basically sails itself. You sheet the jib to the wrong side (or tack the boat without releasing the jib), lash the helm to center and set the main (including traveler and sheet), so that the boat makes slow forward progress to windward on a close reach angle toward the wind and waves.

Theoretically, you should be able to balance the sails to accomplish this even if you don’t have a rudder at all. That's a good project for your next test.

Thank you for sharing the results of your experimentation. It is very interesting.
However, heaving to is not the same thing as "parking," so we have to be careful not to get people confused about the two.

What you are doing with your tests is sort of a combination of the two -- heaving to and parking. Maybe you will come up with a combination that works better for multihulls even though it is different from what is used by monohulls and taught in all the seamanship books.

I'm very serious!