alternate magellan has never been done, but would be as oli said
outside htw nt htw i can accept. but half outside htw nt htw???
the "half" suggests the trick is not fully completed with the htw leg, but comes back to the original foot that touched it up. so if ur right footed... it's left foot touch, right foot rhtw or out htw, back to left foot touch.
but since this is a nt combo we are trying to interpret alt magellen as... then it doesn't matter since it'll still have no touches in between anyway.
you could also call it rhtw/out htw nt in atw.
the nt makes it ambiguous whereas if it wasn't nt, the distinction would be clear.