Sailing dead downwind is usually best done with a symmetrical and no main. I have done numerous tests of this configuration and in the end the best way for this ex racer
to sail square is to put up an old blown stretched symmetrical kite (mine was a give away). It sheets
to each bow. Zero chafe and the boat
loves it, the autopilot
has it easy because the boat
is pulled along by the nose rather than pushed by an oversheeted main.
As we don't have a squeezer I pull the main up if the wind
gets up and I want to pull the kite in ( I can pull my main up on a square as our rig is spreaderless).
I love my screecher for main and foresail sailing but when a reasonable wind
is behind I set the symmetrical. You don't even know when you gybe. A great rig for the cruiser. You get around 45 degrees of wind direction swing before you have to touch a sheet. Richard Woods flew a kite across the Atlantic on a cat with the main in its bag.
the assy got hoisted twice and the symmetrical scores of time. Slightly beaten by the screecher but I would give away my assy before I didn't have a symmetrical to go square with. Any old and strong one will do so they are cheap