Worth it for the ease of reefing in 2.5 to 3-foot chop at Mohave !!!
That Hook & Ring, has "GOT" to GO.

That thing will Really hold all that pressure on the Halyard ?

Only other Cheap solution i can think of is to place a pulley
at the head of the sail then run the halyard through it and
secure it to the top of the mast. YEA the halyard is now twice
as long, but it can now be 1/2 the tensile strength.
Maybe use an electric winch ?

Bille

One of the older Nacra 5.2 systems used a cable halyard that had a ball crimped on it. There was a small fork riveted to the leading edge of the mast. You would hoist the sail and position that crimped ball into the fork at the top of the mast...then tie off the halyard. It was super easy to work with. The drawback was that the halyard tail was on the leading edge of the mast.

But, yeah, I'm quite sure that Ronstan halyard lock will hold. I think you would be amazed at what that will resist.

maybe a small spinlock at the top, but then you'd have to run some sort of control lines down the mast (to open/close the spinlock).

The spinlock would not withstand the mainsail downhaul loads very well. I finally gave up on those on the spinnaker halyard after two of them exploded on me (fortunately right at the finish line both times). They work great for forces induced directly by hand but not behind something that gets loaded up with additional loads.