Whew boy you did the damn thing didn't you Dave!? You must have passed that beaver off!!
My experience with carving on Maples and D trees is limited too, because any time I have done it, the wood became soft, "punky"and rotted away quickly. Not ideal. I'd hit it with some wood hardener or something if you don't want that to happen! I have decided I am just not gonna do it much any more. Maybe a nice hole here or there, but fancy carving, big gaping wounds... Just haven't worked out well for me.
Perhaps olives are an exception to that rule! But Elms, Maples, CM... All heal wounds so fast, I fine a nice diagonal or flat smoothed out cut can normally be healed in under a season for holes not much smaller than these! Obviously it is all about your plan and vision for the tree, but that is my experience.
I am watching with interest to see how this turns out.