Hey G....my thoughts on this...
It seems like you are not too confident in the work of your local shop, expensive green machine or not, and are reluctant to entrust your beloved Kastles to them. I presume this stems from not having had your skis tuned there before. Heck, you probably haven't owned a pair long enough that they would even need a grind

The fact that you are so enamoured with your Kastles and are keeping them this long is really saying something -- good on ya!
So, if from the moment you hand over your babies to these guys, you will be bathed in nervous sweat and be awake at night fraught with worry until the first run after the base grind, then perhaps you should go to a shop that you know does good work (see below).
OK, having said that -- you saw the grind that our shop in Toronto did on Terryl's (that is, formerly yours) rather chewed up Progressor 8s, and on Terryl's Supershape Speeds, and on my first RC4 Progressors. Impeccable. Like new. All three pairs turned out great. Perfectly flat (from base high on the SS, to edge-high on the P-9s). Perfect base and side edge angles, exactly as requested at 1 and 3. You and I were in my workshop and measured and squinted and poked at them upside down and backwards, and couldn't find a fault. And they skied great too! So.....why not bring your skis up here and let them have a
whack (oops -- wrong choice of word)....er, let them have a go at them?
They have a $250,000 Wintersteiger machine which has the ceramic whizzing edge grinding things that Liam mentioned; the techs are serious and conscientious about what they do; and you KNOW the result is good. They can put whatever pattern you want on there, and any side bevels. Whaddya think?
BTW, the shop put an "angular cross structure" on our skis, as a multi-condition performance pattern. Worked great. Very fast -- huge difference over the original tune. And it didn't seem to create any problems in any of the snow conditions that we encountered last winter.
Think about it. And hey, I get it.....I would be agonizing over something like this too if it were a pair of my cherished skis.
Cheers!