The fact that a shop advertises hockey sharpening, does not imply they do or don't do a good job of figure skate sharpening. They advertise to hockey because that is most of the market. The obvious thing to do, as others have said, is to ask your coach and other good figure skaters where they go. Don't be surprised if they don't all agree - sharpening style is a matter of taste. Then ask the shop if they can deal with your Matrix blades.
Flat Bottom V is a trademarked name for a somewhat differently shaped hollow (width-wise concavity) produced by a particular company's patented device. In terms of what actually touches the ice, it isn't tremendously different from the cylindrical hollow used on most hockey and figure skates. But it is different enough that you decide you don't like the shape, and you want the sharpener to put your blade back to a cylindrical hollow, they will have to grind away enough metal that you will have lost at least 1 or 2 sharpening's worth (out of 30 or so) from the blade's lifetime. So unless you have money to burn, or love to experiment, the safe thing is to stay with a normal cylindrical hollow - most commonly about 7/16" radius-of-hollow (ROH - again, a matter of taste).
AFAIK, Flat Bottom V has nothing to do with the rocker (lengthwise convex curvature), so I wouldn't worry about that. Though, yes, a very bad or misinformed sharpener might mess up your rocker, grind off the tail, or remove the toe pick
. Much more likely, they may grind off more of the metal per sharpening than is appropriate for figure skating - roughly 0.003 inches is about right. Or they might create uneven or inconsistent edges - though most hockey players hate that too.
I've heard good things of
"Mr. Edge", around Chicago, which is fairly near Canada. But Canada is a BIG country, so maybe that is too far. If you aren't pickey, you may not need the best - someone who doesn't make any major mistakes will do. If you are pickey, you may eventually decide to do it yourself.