Success! Sort of!
First sail went fine, but I found a fair amount of water inside the boat when I was done. I decided to use some foam insulation tape to seal the hatch a bit better and put some 3M 5200 around the rudder post, just in case that was the problem It's never coming out now!
I took it out again and got a tiny bit of water inside, so I think my hatch sealing effort did some good, though I did not get the boat blown down as often or for as long on the second sail.
I took some video, but it was difficult. I was holding the camera with my rudder hand, so I was trying to steer with my elbow while shooting video and trimming the sails with my other hand.
Then it occurred to me that my fancy new remote control made that unnecessary. I unplugged the rudder servo from the "aleron" spot and put it in the "rudder" spot on the receiver. Now the left hand control stick does the sail and the rudder, so I have a free hand. I haven't tried it out yet with this setup.
Here is today's video: