A process for writing an already outlined chapter

I'm in a late stage of my ridiculous sprawling fanfic; I have written complete chapters for all major moments and most of the minor ones, and now I'm filling out the less consequential beats that help get my characters from A to B both physically and emotionally. So my process is character-oriented rather than action-oriented. The unwritten chapters are defined by specific conversations: I know roughly what needs be said, and then I figure out set dressing that strengthens the conversation. My process goes like:

• I know that in chapter #52, Alice needs to tell Bob that she feels bad about Eve's death which she feels she could have prevented.
• I already know that in chapter #57 the two have arrived in the desert town of Jonestown to meet Eve's family, so the setting will be the changing landscape, becoming more arid over time.
• I will make Alice stand in a dry riverbed (googles reference images, asks chatbot for temperature estimates and what clothes they would have to be wearing) and attempt to climb the sides; Eve was a great climber so that's relevant and loaded.

It works. I'm productive. And all these chapters look the same:

• Opening paragraph with some notes on the surroundings.
• Opening dialogue lines with some notes on the (inconsequential) action they're engaged in
• Actions and dialogue lines roughly alternate, matching mood (actions struggle when characters struggle to articulate their feelings)
• The chapter ends when the important things have been said, randomly with a line of dialogue that feels punchy enough.

I'm exaggerating a little but not much, and I didn't realise how bad it was until I noticed that I had started three successive ones with almost identical weather descriptions. And I'm not exactly the greatest dialogue writer so that doesn't carry them either. Hence, I'm starting to question the process. Sure, my audience will be myself and three scraper bots on AO3, but I really want to feel happier with what I've been doing.

The thing is that I am long past exploratory writing. I feel like I need to get into some assembly line mindset with these chapters; these beats that are already outlined, that are defined by the (small) developments they need to carry. These do not have operatic revelations or any non-trivial stakes, but they move people places such that over the longer story the changes are gradual.

How can I improve on my process?