Hey,
I was just playing with the tool and noticed that when I set an aura for a token and select the "square" option when I'm using a hex map, the aura is indeed square (duh). However, this does not match the hex grid.
Perhaps another option could be "match grid" and then the dimension would be given as a "radius" of hexes or squares. So if I chose "match grid" with a value of 1, the token's hex or square and the first set of surrounding hexes or squares would be included in the aura.
Thanks,
Matt