Dennis,
That's exactly how I have the spin rigged on my FX-1. It's a great setup. I tried to use a spinlock on the mast for the halyard like the F-18 guys do, but sailing singlehanded, the angle was wrong. And the slightest bump would cleat the halyard. Flipped a couple of times from that. I had to get too far away from the tiller
I just used a Ronstan swivel cam cleat on the fwd xbar. Take the strap off of the top of it so that you can flip the swivel 90deg and get the halyard completely out of the cams. Sometimes if the halyard rests back on the cleat, the line would re-cleat itself during the douse.
There are a few diagramshere.
Scroll down to sails and look at spinnaker setups. Or scroll to the FX-ONE and tiger diagrams.
Hope that helps. You're system looks great.

J