It could be he is waking because of the teething and is using those feeds to get himself back to sleep - a comfort thing
Are you medicating for the teething at bedtime? A dream med can be good for getting them through the small hours too.
At this age he doesn't *need* a nightfeed but you may have to activly wean it if you don't want it to continue for much longer. If the second feed is much smaller I would start with that and just offer water when he wakes. I'm sure he will protest and you will have to settle him in a way he responds to and be consistent (no caving in
).
We weaned my DD's NF at about 8 months by reducing the milk in the bottle 1oz every third night and then only offering water if she woke (she slept through one night when the bottle was down to about 3oz). She wasn't impressed but we stuck to only offering water and she only woke another 2 or 3 nights when there was only water on offer.
His 24 hour milk intake is good, have you tried offering a bit more milk in the day to move those night calories over? How is his solids intake? You could try increasing his solids a bit to see if that helps too.
Laura