@tty the slot may be enough to jam the line, but if it isn't you can probably just wrap it around the boom or mast once afterwards, and then maybe run the end of the line under itself to lock it. Adding like a thin nail in the mast to wrap the line round once before locking it might also work, like a sewing machine does for tension?
@rek Great ideas. I'll let you know how it goes >:)
EDIT: as soon as some heckin' wind actually comes this way
Sunbeam City is a anticapitalist, antifascist solarpunk instance that is run collectively.