Tom, we were out in the same breeze on Saturday and Sunday, and enjoyed an overnight stay in your harbor Saturday night--my first stay there in at least 40 years.
Our solution to your issue is a simplified variation on the "lazy ring" strategy already mentioned. It consists of a single strap of strong webbing with a generous (say 5-6") loop sewn into each end. We drop the halyard, rig the strap through the cringle, and attach the loops over the hooks on either side of the gooseneck, then take up on the halyard. Our luff slides are "locked in" to the mast track, so we usually need to release the 2-part downhaul and lift the boom relative to the bottom sail slide, in order for the same strap to fit lengthwise over the gathered slides of the second reef. After securing the strap, we then retighten the downhaul before tensioning the halyard.
On Sunday, we found ourselves overpowered occasionally in gusts around 30, even with the second reef in. (I conclude our new high-clew 100% working jib is a bit too big for these conditions.) So I tied in our third reef using the same concept but a longer strap previously made to measure. This was the first time we have tried the third reef, and I was as pleased as I expected to be. We don't have a turning block on the boom for the third reef line, so we actually used the now-unused first reef line, which required more tensioning than I could apply without a winch, but the outcome was still acceptable. I think I will add a small winch to the forward end of the boom for this purpose, as it is also a challenge to tension the foot at the first and second reefs.
What a beautiful weekend on Maine coast!