NOHUHU once suggested tying the mainsheet to the furling line (as we all do anyway), then attaching the loop you have made to your PFD with a carabiner. I tried his idea and it works great. -- Ironically, I have a feeling that NOHUHU may not have adopted his idea.
I must say I sail with the mainsheet uncleated much of the time. I find I need to adjust the trim of the sail almost continually for best performance.
I still like the idea, but admit I've not found a big caribiner to do it right.
But I do keep a death grip on the sheet at all times, especially out on the Hakas. I trust and use the mainsheet cleat. A TI sail can quickly fill and the sheet may exert loads of well over a hundred pounds of pressure. Using the cleat helps keep my shoulder in its socket and my arse on the benches.
Sharris, I usually crew and pilot the TI from the front seat (Hakas actually) so I don't experience that open cockpit fear factor, but in your case, using a simple surfers or SUP leash will give you all the confidence you need.
If you are wondering about how your boat will react without you, just try it.
I mean, give yourself some room, get on a tack and just release the rudder, watch what she does. Release the sheet, watch again. Release the furling line, etc. Put her in irons, too, let her backwind,.. let the boat do what it naturally
wants for as long as you can, then recover. You'll learn very quickly, and realize you don't have to be in tight control of the boat at every moment.
Then move on the harder stuff, reading the sail, heaving to, using a paddle to steer (simulate broken rudder) and landing that way. Replacing a rudder pin on the water. Surfing,.. capsizing.
A TI is a great boat to learn on with the help of an experienced old dog, like KayakingBob, for example. It's harder trying to yell advice to each other from a couple. PLUS there's the collisions,..
As far as what happens when someone is "thrown" from the TI - The boat will almost always turn and slow (for awhile), probably to windward, so anticipate this and it may help you get back on.
FWIW, I've dragged people in the water in decent wind, and the AI/TI slowed dramatically to a crawl, and turned in the direction of the drag. If it's a downwind jibe, (or turns into one), that may be the only tricky recovery.
If you find yourself "prematurely ejected" from the cockpit, my best advice is to swim to the stern and grab the rudder. Steer the boat into the wind. Everything after that will become a lot easier.
Hell, you could probably slowly sail it all the way back to shore that way!