As you have summarised correctly, there are benefits to the aft mast position, but just plonking the mast in that position does not mean it will a great solution, without, as you say, consideration to the engineering required. I cannot figure out how the Lagoon 39, or 52 for that matter, are engineered & built properly to support it, and got no answers when asking about it from Lagoon. If you have a pipeline to VPLP, I'd be curious to hear their answer.e
By the way, VPLP saw Nathan Stantons FF52 being built in China
by an owner, and subsequently the Lagoon boats appeared, but that's another story.
I have researched this fairly extensively, and IMHO the Stanton boats are properly designed and built to carry the mast in that position. In fact,they are specifically designed & built to do this, and the structural and composite engineering to pull it off are not easy peasy.
But to my mind, it is worth it and one of the reasons we chose the FF46 as our design, after considering pretty much everything else.
It sails beautifully on all points of sail, and especially through rough water
I spoke with owners of an FF52 who went through a brutal test sail in big, short chop, and they said they had never sailed on a boat that performed nearly as well, and they put their deposit down immediately after the test sail. They had test sailed every boat I know of over the previous 3 years looking for their ideal circumnavigation liveaboard
, and settled on the Freeflow for 1, the performance & 2. the sail handling advantages of the wishbone aft mast rig. No traveller loads, easy manual sail handling by a cruising couple, even elderly vintage types like us.
There is one disadvantage and that is, compared to a Bermuda/Marconi rig, it is not a raceboat for close reaching upwind courses, compared to a large roachy main driven boat with smaller flat jibs. But for cruising, it is excellent.
Beware of aft mast boats without the proper engineered solution. And BTW, the reference you made to the champher panels
being carried back on the bridgedeck are part of the engineering solution, and they soften the ride in lumpy confused seas, as well as give great bouancy lift
on downwind surfing conditions.