Perhaps a hybrid of sorts would help. My uncle throws no-thumb and has his equipment drilled half-thumb like Tom Smallwood. He uses both releases depending on the conditions. His thumb hole is off to the side much like you're describing, and only goes to the first knuckle.
If you have an old junker ball you don't use much, maybe you can have one punched out to test it. Do whatever feels best and most comfortable.
---------------------------------------------------------------------------------------------------------------
There is nothing so easy to learn as experience and nothing so hard to apply