Hi Bananers, for a 12inch p-stem, the Truly Tiny is a big guy so you can safely separate the pup and repot it separately. Remember that this plant grows to only about 2ft in p-stem height so it's half way there already.
I have a couple of these Truly Tiny in the ground and they seem to be the very accommodating lil fellas. No complains about anything and pups quite well. I guess there's nothing much more to say about this cultivar except to enjoy them!