I help deliver a 50' boat a couple weekends ago. We sailed all night on a run wing on wing. Wind was about 15 knots. Under those conditions I would usually rig a dock line from the boom to the rail as a preventer as it is really hard to see the sails in the dark.
There are some disadvantages having a preventor that can't be released easily too but still it seems the lessor to two evils if you don't have a real boom brake.
All he did was leave the traveler uncleated on both sides. When we did inevitably jibe the traveler pulling it's line through the blocks has a pretty good damping effect.
I'm not saying I would do it myself except in very light air but it did seem to work. The rig stayed up.
That trip was with me. David joined after I sailed all day solo over to pick him up. He's a great help and I highly recommend him.
We have a boom break in the cockpit locker. I didn't feel we needed it yet, but would have pulled it out (or rigged a preventer) at the least suggestion. I like using it and the special line is used for only that purpose. We have the smaller mast = smaller sails, by the way, and the wind was unchanging in speed and direction and not gusting at all. The boom is above the full bimini hardware and the solar panel.
(I think boom brakes are far safer than preventers, by the way.)
The traveller setup was not intentional as a boom break.
More importantly is that all suggestions are welcome at any time. Maybe I should add that as a standard practice, to periodically solicit ideas on what we could do to sail safer or better. I like it!