You may well have stumbled onto a brilliant technique here, Maureen! Great way to start the knitting new year!
I'm pretty sure that it's the right hand needle, the one you form the stitches on, that determines the size of the stitch. When you're knitting from a cable needle, for instance, it's usually smaller than the needle size you're using for the project yet the stitches come out the right size. And that, I believe, is because you're forming them with your right hand needle which is the correct size.
If you were knitting flat you might have a problem with the differently sized needles, but knitting in the round, your right hand needle is the one that consistently forms the stitches.
So it sounds like you're in great shape with this and the next project I have on circs I'm definitely going to try it out!
Thanks for writing in with this and have a happy knitting new year!