He could have written it instead as selfish vs pleaser routes. Her doing it more for her own pleasure vs trying to get her husband off better. I think that's the bigger divide cuz no matter who's topping it depends on how someone gets their rocks off.
Just so we are clear, you do understand that current Amelia is aiming for mc's pleasure and not her own? For Amelia the other guys are more like props she uses to satisfy mc's fetish and her own enjoyment comes from satisfying it. If the mc would had said no when Amelia hinted about the co-worker she wouldn't have done it. She wouldn't have been disappointed and thought she missed out on sex because only reason she even considered it was to entertain mc.
The point is that Amelia doesn't treat mc's fetish as a free ticket to satisfy herself. This is shown well with Geist situation, which you brought up in one post as good writing. Even though she was already bit annoyed with him during it she allowed Geist to boss her around and finger her. It wasn't because Geist's fingering was so good. As she later told Geist only reason she let it happen in first place was for mc's enjoyment. Another good example is when they are in the sea and Amelia is about to walk topless to the shore and mc panics to stop her. Instead of teasing him about it she reassured him she isn't going to do it. Her plan wasn't to satisfy her own need for exhibitionism it was for mc. It's also my favorite scene so far.
I have read enough of your posts to know that you don't want the game to be vanilla but somewhat softer nts. Unfortunately that type of nts only works in short form because there isn't much to go for. Maybe if you tried to see Amelia's actions more like elaborate stories you could enjoy the game more.