Expectations vs. Boundaries vs Manuals

Hi – I’m really struggling with how to differentiate these and use (or not use) them in the best way when it comes to relationships.
Specifically, how to state an expectation (with the understanding that the answer might be “no”) and follow through with a boundary (that only I am responsible for, if necessary) without having a manual for another person

Me – “Since we both agree that our conversations often do not end well, I’d love to talk with you to make a plan on how we can better communicate in the future”
Them – “I’m over it and don’t care to talk about it anymore”
Me – Ok. Just know that I will probably not be reaching out in the future. If you ever want to talk more and make a plan, let me know!
Them – “Whatever, sure”
C: Conversation
T: I want to have a better relationship with x
F: Hopeful
A: Make a request to make a plan together knowing that the answer might be no
R: x declines so I create a boundary to not reach out moving forward