While I would rig a preventer to the bow if I were in the same situation,...again. But me and my boat are coastal sailors, and that means something simple to use is what will get used. The strap works fine if the main isn't reefed or as Paul has it, the sail is slab reefed so the strap can go under the sail when it's reefed.

It just won't work as a preventer to the end of the boom. Preventer is middle of the boom only.

What I like is the simplicity of snap shackles needing to be attached to the deck fitting, or genoa track slides with loops(I have them all the way forward on each side for this purpose). The line led back to a cockpit winch allows easy adjustment of mainsail twist. And it's simple to let it run through the snatch blocks to tack-resnap the snatch block to the other deck fitting or genoa track when it's convenient.

This thread also makes me realize I have pad eyes at the bow for a preventer, I just never knew what they were for. However, you better rig this long before you need it. It's one thing to snap a snatch block a couple feet out of the cockpit on my boat with it's wide side decks, high toe rails, double lifelines and solid stanchions, quite another to go to the exposed bow.

Slotted metal toe rails hurt me in so many ways.