I hve a ‘free-flying’ storm jib on my B32 ‘Another Fantasy’. I use the spinnaker halyard to hoist the sail and fix the tack to the fitting on top of the Furlex reefing drum. I’ve used this arrangement in anger a couple of times and it works well enough so long as the halyard is kept really tight. If you’re planning on using the storm jib regularly I’d recommend fitting a spare forestay and halyard with piston hanks on the storm jib.
Hope this helps
Ian Culley/ Another Fantasy