I have this theory that us Mac people are possibly going the wrong way with the masts?
A couple things you might want to consider first. One is that in the picture above they have baby stays attached to the boom to help stabilize the whole deal side to side. Once the mast gets above where it is in the picture they are going to do very little. Maybe there is something else out of the picture that we can't see.
Now the real deal breaker for me would be that we trailer with the ....
....foot of the mast up forward on the pulpit. Then we just slide the mast back to the deck plate on the cabin top, which is not that far away. One of the great things about the Mac is that all of the shrouds and backstay stay attached and are in proper tension once the mast is up and the forestay is pined. You only have to adjust it and some don't.
Now if you are going to use the boom you have to get the mast so that the foot is trailed at the back of the boat or turn it all the way around before raising it. How are you going to do that and also keep all of the standing rigging attached? Also if you do have it turned around on the trailer and will put up with reattaching all of the rigging you have a long ways to move the foot of the mast to the cabin top and while doing that what is going to be supporting the mast ahead of the boat?
Also on our boats the forestay tensions the rigging not the backstay, so if you raise it like in the picture you have to keep the mast from coming over backwards. That means attaching the forestay first and the backstay last. Next you would then have to go back and mess with the forestay tension again. I think from your other posts the CM has a different shroud setup vs. the fractional rigged Mac, so what they are doing will work on that boat, but would be a real mess on the Mac as far as I can tell.
The Mac is one of the few boats that you can store and raise the mast without messing with rigging tension except for the forestay. Why get rid of that great plus? I think I'll stick with my little gin pole. If we can get enough supplies on the boat for over a month on the water with out re-stocking and can still get the gin pole aboard I think we are set

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