Thanks very much for the suggestions.
About the mainmast stay sail, I got it into my head, I'm not sure from where, that it was not usually used. Do you know when it would be used?
Removing topgallant masts is something I would like to add to the game, along with studdingsails. The problem with both of them is that there is code at the moment for breaking things off the ship, but not really for sticking things on. Hopefully I will get to it someday.
Where can I read about lowering the yards? Was it something that was done to reduce sail quickly, say if there is a sudden change in the wind?
I thought a lot about how to handle anchoring, and was at one point planning to put it in the last build. Maybe next time.
Sadly too much stuff is hard-coded now to want to mess with different rigs.