We often sail the Bucc18 with the mainsail luff 'soft' for several feet.
Is this what you call it when you ease the main and get a big, backwinded bubble in the forward third or so?
The other day I was in ~18mph or so and hadn't reefed, and doing that seemed to be giving me a good ride. I was concerned it was making me look like a dope, though, so I hove to and reefed before long. ;-)