instead of assuming gender, why not just assume sex? The difference? Sex refers to biology, (XX vs XY chromosomes, sex organs, etc) where as gender refers to perceived social roles based on sex.
My definition of those words are different to yours.
Gender to me is with regards to your physical make up. XX chromosome denotes a female gender. XY denotes male gender. It does get blurry though when people have operations to alter sexual organs or hormone levels.
In such cases, it doesn't matter what I think, it only matters what they think. If they want to be referred to as having a specific gender, then that is politely how I will refer to them.
"sex" to me is an act of reproduction.
When I speak to people, if I use the pronoun he or she, I’m referring to their sex not their gender.
If a person looks physically male, I will use "he" and if physically female I will use "she" - unless this person has otherwise told me what pronoun they would like to be recognised as. If they are obviously transgender then I will use the pronoun of what they are trying to be, rather than what they physically appear as (to me) unless they have otherwise told me what to call them.
At all times I try to be the utmost respectful to them, to the person I am conversing with or referring to.
Respect is the key.
I’m making an assumption of their biology, not whatever confusion they might have going on inside of their heads.
I would consider this approach to be stubborn and disrespectful.
It doesn't hurt to be respectful does it?
Just like when Cassius Clay changed his name to Mohammad Ali.
To respect him, you need to call him by his preferred name. You don't get bonus points for calling him Cassius, you just annoy him. Why do that?
If a biological woman identifies as a man, she shouldn’t assume I am addressing her identification when I call her she, this woman should assume I am referring to her biology.
Why is it so hard for you to respectfully address her, how she wants to be addressed?