Re: Trysail vs. a fourth mainsail reefing point
I'm not the the same league as most of you, but I have a trysail on my Thistle.
I took an old jib, cut off the hanks, and replaced them with slugs that fit in the slot in the mainmast. Spinnaker sheets lead just about right. Sail is about half the size of the double reefed main.
Worked very well the one time I used it. Good control at all points of sail except dead down wind. Pointed very well. By using existing slot and halyard on mainmast, and existing spinnaker sheeting setup, no extra rigging or hardware required.
Your mileage may vary.
And the Binnacle-bats wore water-proof hats
As they danced in the sounding sea.