@Cman, my guess is that your sailmaker was worried that there wasn't enough intermediate shroud tension to check the middle of the mast aftward, and they were worried about putting too much bend in the mast. In any case, having the leeward shrouds flopping about should be your warning that the rig isn't set up right for heavy air. (And theoretically, unless you have the right pin check system, everything could catastrophically work loose.)
The warning sign for too much bend in the middle of the mast should be tack wrinkles in the main that a reasonable amount of Cunningham can't pull out. I sail in San Francisco with a rig (usually) tuned quite a bit beyond the top end of the guides. With this setup and my stay lengths, it's hard to put too much bend in the mast unless you go beyond the 2" of ram.
FWIW, I've found the guides not well calibrated for our heavy air (20+ true). Loos tensions and turnbuckle turns beyond the "heavy" recommendations still result in somewhat slack set of leeward shrouds. The local riggers recommend ignoring the guides for heavy air and keep going tighter until the leewards stay still, but I've been wary about going this tight. So I've, perhaps naively, settled for somewhat slack leewards in the heaviest, but always with a straight-to-the-eye mast.
Otherwise, @11235's recommendations seem right to me, although sailing short-handed, I haven't gotten vang sheeting to work quite as well both with speed and with handling.
Also, I ease the inhauler before dropping the traveller below about centerline, but I might be doing this sub-optimally. Inhauling in 18+ seems counterproductive, as the "luff-up-a-little mode" groove gets too small and its very hard to keep all the telltails flying just so.