I am the OP! And it has got better.
4 months was a nightmare, 6 months started getting a bit better and then plateaued, and then from about 9 months we have seen a gradual improvement. He's now just over a year and still wakes for a feed but not till around 4 or 5 am, and the day naps are MUCH better.
I only did very gentle things, making sure he came off the breast before falling asleep, gradually cutting his feeds shorter and shorter, and then he dropped most of them himself. One I got rid of by patting and cuddling him and again after about of week of that he dropped that one too.
I know by a lot of people's standards waking once in the night at his age is still not 'good enough' but for us it's fine, I can get enough sleep now and we're all happy!
I think a lot of it was to do with genuine hunger, I think when younger he really needed all that milk. Weaning helped a bit, but most of it I think is just maturity. But yes also he does flip onto his side or tummy now to sleep and that has helped too.
Anyway thanks to all that posted, and those of you in the same situation now, take heart, it will improve!