Sometimes wakings get habitual and babies of this age are wanting to suckle to relax again. I understand your supply issue. I've done tons of herbs, teas and prescriptions to boost mine. What a nightmare!!

one thing I've done is pump in the middle of the night and save the milk for a supplement after the bed time bf.
At this age, in my opinion its very confusing to feed sometimes but not others. I don't think I would do that. He really don't need any calories at night. He should be able to make it just fine... Now that being said, he's used to getting them at night as well as they day. So he doesn't 'tank' up as much as he should during the day b/c his body knows its available at night as well. And its so relaxing he enjoys being able to suckle when he wakes instead of just going back to sleep himself.
How's he doing with his solids intake?
Since you are having a supply issue have you offered a supplement after your bedtime bf? (either expressed milk or formula) To see if he's getting full enough before bed?
How many nwings does he have and how close together are they?
Does he take a paci? You could use this to help resettle him.
Your goal at this age is probably to get him to get most of his calories during the day and not at night..... You could even think of a dream feed... I've never done one at this age (I weaned mine from df's about 8 months or so... after solids are established well) but you might give it a go. That way it can help him get more calories while you are encouraging him to sleep longer at night. So if he wakes up really soon after the df you know its not hunger and its def habitual and he's wanting to suckle to relax again instead of just falling back asleep. DF might help you get a little more calories in him while your teaching him to fall back alseep by himself and not have nwings.
It seems like you still want to consider bfing at night. If this is just for your supply issue I recommend pumping at night as to not encourage lots of habitual wakings that he gets used to suckling to go back down after.
If you want to bf at night regardless of the supply issue I'm not sure how to guide you on that. But I'm sure you will get plenty of advice if you need it for that.
This is just what I know.
Good luck!!!!!