Hey, thank you for noticing! It's easy enough to add/change a line or two based on other events as long as I remember them, and I thankfully have a pretty good memory for details. But sometimes it's a much bigger ripple through the story, so I do a lot of playthroughs going through different paths, taking notes on things that would logically come up or change based on past events. It is a lot of effort, but I think reactivity is what makes doing multiple playthroughs fun, so it's worth the extra work.
I do sometimes wonder if anyone will even see certain scenes - like, there's entirely different dialogue for Dominic if you hung out with him, propositioned him, went to the club with Isaiah, and then speak with Dominic while searching for Isaiah at the end. I have no idea if anyone would take that path, but it's possible someone would, so I want to take account for it!