It's clear you've been trying to increase the intervals - I presume you've experimented with increasing the intervals gradually - and that his cues are showing you he still needs to eat. There may be a few other things you can try which I'll talk about later.
But first.
Apologies for those who have heard me banging on about this before:
It's possibly your issue may be related to your breast storage capacity. That is not remotely to say that there is anything 'wrong' with your supply - over a 24hr period your milk supply may well be higher than people who can have longer intervals - it's a separate issue.
An Australian doctor finished some research a couple of years ago that confirmed the view we can't make hard and fast rules about how long babies should be able to go. We sadly can't know what Tracy would have made of the research due to her passing but it revealed some quite new findings.
It had previously been thought that mothers had roughly the same number of milk ducts as each other - thought to be 15-20. It also used to be thought that mothers had larger milk 'reservoirs' where the ducts widen but we now know that was as a result of the way the breasts used to be studied (injecting hot wax into cadavars which distended the duct shape - yuk). So Dr Peter Hartmann found through his research using modern scanning techniques that women don't have these wider areas but that duct width is fairly similiar throughout. And he also found also that duct number varied enormously in his sample - 20+ or as few as 4! The average being about 9.
Storage capacity does not determine how successful a breastfeeder you are or your supply as I say but it does affect your intervals. Milk production happens continuously but storage capacity is a factor. You can't tell by looking from the outside how many ducts a person has. It might well be that you are someone who has a slightly smaller storage capacity than your mate who is going 4 hrs.
Intervals are also affected by habit and what breasts are used to producing. So some women with larger capacity can get themselves into a pattern of shorter intervals which they can break by increasing the intervals gradually to get baby and breasts accustomed. But if you've tried that and it's really not working, it might be that you've reached your natural point.
If you want to try further - some women have more luck with trying to increase the volume of a feed as much as they can - using the 'third side', breast compression, pumping after a feed has finished to try and send signals to increase production. And then use distraction to encourage baby to last longer. But if all that doesn't work - you obviously have to respond to his cues as if you don't, that means a hungry sad baby but also a possible risk to your milk supply. Tracy felt that the longer the interval - the better the baby will feed; which works until you factor in this new research as I say.
On the positive side his nights sound good and because his one waking after the df is so variable in time it sounds as though he is simply hungry (which isn't unusual at this age). He will need to take in a certain amount of calories in 24 hours and at the moment it sounds as though he's achieving that well.
As he gets older and his awake time increases, using an EASY structure will obviously become difficult but the most important thing is that you avoid a nursing to sleep association as this could affect his sleep habits during the day and night.
So certainly have another go at extending intervals and encouraging your supply to adjust - try and see if you can at least get to a consistent 3 hrs as an aim. But if you've had a good go - don't despair. You may have reached a natural plateau and that is fine.
(And 20 years ago - your health professionals would have been adamant you should be using 4 hr intervals and you'd probably not be breastfeeding by now. A very simple contributing factor for the dramatic decline in breastfeeding rates in the 1960s and 1970s was the insistence on the 4hr pattern and mothers who couldn't manage it ended up supplementing and weaning).
