I like the idea of the hole in the sail box. Now that I have one -- I just might try that.
To date, I've been hanging mine below the mast. Pass two web straps, by the inside front and the inside back of the tube, between the pole and the snuffer tube. Take the web strap back through one loop, that you have previously sewed into each end of the web strap (or bought that way). Match each web strap with a short bungee cord that is tied around the mast, keeping one end free; keep the free end of the bungee cord short to minimize swing. Catch the second loop of the web strap with the free end of the bungee. The pole and snuffer is now hanging below the mast. Using rope, tie the front part of the pole to each side of the bridle wire brackets and the back to the each side of the rear crossbar. I use the hardware on the spinnaker pole to aid in this step. Take up the slack on these lines.
The whole assemble is very stable -- on my rig, I see very little swing. If I remember right, I postion the bungee so that one is in front of the mast spreaders to prevent slipping.
I found this to keep the wear and tear down on my snuffer tube. Plus, the lettering on the snuffer tube is great advertising for Hobie.