I'm still pondering if there is any significance with the honeycomb holes being hexagonal and if it would work in exactly the same way with the plate or plates having round holes in them
Yes, the honeycomb holes would help the reaction by the so-called CSE.

Grebennikov was one of the last researchers with remarcable results in the field of Cavity Structure Effect.

You can find out about his work here: http://keelynet.com/greb/greb.htm