Re: Trysail vs. a fourth mainsail reefing point
I've drawn, and used boats with trysails as part of their working wardrobe. Use it to balance the boat when sailing with a small jib or storm jib rather than as a "driver".
It works well, with the boom lashed down in its gallows and the main well furled, the storm trysail high enough up so the clew is above the crews heads in the cockpit it works well.
In some of the smaller yawl rigged boats though, I use the mizzen to do the balancing.
An expert is but a beginner with experience.