April,
You need to post photos of the type of detail that your plotter can make as a comparison. I would believe that a laser can easily match the detail you need (can easily cut detailed letters like what you are reading here), yet still be easier to weed out that a plotter cut stencil. All this talk about the rolled edge of laser cut edges is likely not going to be an issue, and can actually be helpful in stencils, as the tiny (I mean barely discernable) lip might actually help prevent "bleed under" of paints.
The tiny melt lip of laser cut mylar is bad for gaskets, but I can't imagine bad for application on human skin. Nice thing too is that you can apply a low tack adhesive to the mylar for sticking it down. Can your plotter cut through mylar with PSA adhesive on back? Likely clog your knife.
john.blazy_dichrolam_llc
Delta Unisaw, Rabbit QX-80-1290 80W Laser, 5 x 12 ft laminating ovens, Powermax 22/44, Accuspray guns, Covington diamond lap and the usual assortment of cool toys / tools.