Hi and welcome to BW!
If DF is not working for you then don't bother with it. It might be that it will work later on for you (that's how it was for us).
If he goes to bed at 18:30, wakes up 2-3 times a night to eat and wakes up at 6 he is actually having a really good night. I know that for us, parents, it's hard because we just want our sleep and sleep ins, but I'm afraid life just has to change.
How many naps he has a day? If you manage to put another nap in there then you could push BT to 19-19:30 and then perhaps that will move his WU to 7. But like I said, there are no guaranties and for a baby his age to sleep 11.5h a night it's just amazing.
Also, don't be worried about the 3h cycles. He is still very very young so if he is having 2-2.5h cycles it's also ok.
And if he is not hungry when he first wakes up in the morning then you can try and feed him a bit later, closer to his nap, but have a short A time in between the feed and the nap so he doesn't associate feeding with sleeping. Even a nappy change is enough.