Hey there, thanks for sharing! I think you nailed it, it did feel like a simulator, not a novel to me and I think that's what bothered me. There's still that charm to it though, you do feel like you've known this guy your whole life.
What I said about part 3 specifically refers to the section about Terri (y) and Miranda having a fallout. As someone around that same age right now (recent highschool grads), I feel like no one around me would have that much trouble articulating and communicating with each other as they did, but again, personal experiences always vary. That section alone aged the group down to like middle school kids' arguments. For me, it really put me off the immersion. It just feels disappointing to see that interaction, since I expected more emotional maturity from their characters.
Also for step 3 the parents farmer's market trip moment was very strange. Again with the not communicating to each other as grown ass adults basically.
This did get better moving towards step 4 when Cove and the MC started talking about their futures and life together, which does match up with what they'd be feeling at that stage in their life. Another thing I noticed after finishing the game is that the extra characters do feel like they're just thrown in there and I don't really feel attached or interested in any of them. I know there's the option to interact with them more and kinda bring them along into the next steps moving forward like with Shiloh, Jeremy and Baxter, but I honestly didn't miss them at all. Not much value added not much value taken away for me. They're just there.
Cove and the MC do come to the flower field a lot! Several times in step 3 and 4 each I believe. I'm not sure which section you're referring to though, I might have missed it since I had the affection level to Love since step 3 and set them up to be already dating when starting step 3 and already engaged starting step 4. I do wish I went for a more slow-burn type playthrough since just having it maxed out did make it more boring for me, but I might revisit it in the future : )