I've used it with 2K base coat for years and it's fine, you just need to apply the mask thicker. Also make sure you have a tack cloth and air blower to hand as it doesn't stick to the mask and as you peel it off it just flakes and goes everywhere.
However DON'T try and mask it with 2K solids (as in those that use hardeners), we tried it as we had to do a logo in a very specific colour on a van... needless to say the trainee spent the rest of the day sanding off the paint and the mask
