I'd be interested in seeing results on that, let us know, ok?
The design otherwise was meant to reduce the baseplate to a real minimum, because it was a design limit with previous blocks. The multi-hole has the advantage of acting both as fins, and help the structure.
Your design can probably go very thin, but you'll probably be limited by what the clamping pressure is going to do to it. You ought to be able to reach a 1mm baseplate, lower if it holds. Cascade is a hair...
