I have cut latex thicker than that - people who build masks do it all the time. All you need is the right pair of scissors. Sadly my old handplates don't have the needed thickness at the front, or I'd show you...
If you look at the supersize Hero picture, you can see that there is a faint "wavy" line on the handguard where the indents would be, but no knuckles cut, and it looks very dark beneath. I'm sure I've seen another pic were it looked like the weren't completely solid, still looking for it though.
you could cut those out with scissors easily, on the other hand, you'd probably get a more tidy result with a dremel... but are we really looking for a tidy solution here?