Cluster feeding is definitely a thing and always has been! You definitely did not invent it @Fieau My PIL have some very strange ideas! Mine are convinced I am trying to freeze him to death because I don't have him in 46 layers of clothing!
My daughter cluster fed and was really calm, and I just sat up for hours and drank tea, ate biscuits and fed her. It was a lovely time. This time with my son, I don't actually think it's cluster feeding. He wasn't napping brilliantly in the day, therefore not feeding well, which culminated in hours of screaming. I resisted the dummy (stupidly, as my daughter hadn't had one) and didn't really persevere with it. Now he has accepted it, he settles quickly for a nap and stays asleep for much longer. Fed more efficiently yesterday and went down at 8pm. Woke twice, fed, and then was up at 7.15am. Very early days, but I think lack of decent daytime sleeping is/was the cause of my particular issue.
It's is so hard not to compare to your other children! I constantly have to remind myself that he's a totally different baby! My daughter lulled me into a false sense of security! 