Newer Hunters with a "rigid" vang usually have the Selden Rodkickers installed. Selden says they should never be adjusted so they bottom out, they seem to be well damped and with the vang, topping lift, and short mainsheet from the end of the boom to the arch so the boom seems contained pretty well.
As far as the boom touching the arch, if the sail is all the way up the mast and the boom touches the arch or the bimini then the sail is either stretched or not properly cut. Company's like Hunter, UK and Doyle do not put boats and sails together that are not designed to be adjusted properly.
I know there was a problem with sail cut on early 356's so that there was leach flutter on the mainsail, UK fixed the problem quickly.
It seems to me if you can't flatten the mainsail then the sail needs to be fixed, the boat does not need to be redesigned.
Bob
As far as the boom touching the arch, if the sail is all the way up the mast and the boom touches the arch or the bimini then the sail is either stretched or not properly cut. Company's like Hunter, UK and Doyle do not put boats and sails together that are not designed to be adjusted properly.
I know there was a problem with sail cut on early 356's so that there was leach flutter on the mainsail, UK fixed the problem quickly.
It seems to me if you can't flatten the mainsail then the sail needs to be fixed, the boat does not need to be redesigned.
Bob