My DS is 8 weeks old - he is breastfed, supplemented with 'comfort' formula, usually once in the morning and once in the evening. He mostly feeds expressed milk from the bottle as he has a habit of falling asleep on the boob. In general he is a happy and settled baby and I have no concerns. He's gaining weight very well.
I've noticed at night he will have one long stretch of 3-4 hours from about 8pm, and afterwards he will wake more often (every 1-2 hours) until finally 'waking up' ready for the day at about 6.30am.
When he feeds at night (whether boob or bottle - I've experimented with both) he will only feed for a few minutes, if that, before falling back to sleep. By morning my boobs are very full but he doesn't seem any hungrier than usual.
If it was you, would you be trying to settle him back to sleep at night, rather than doing these micro feeds? I'm convinced that sometimes he doesn't even feed, just comfort sucks, if you see what I mean.
I'm wondering if this is a stage on the way to him sleeping through...
PS. We co-sleep. Not sure if that makes a difference!