I do this a lot too, and most of my friends are very understanding, which has also prompted me to get better about remembering what they were saying so I can recenter the conversation on them once my tangent is over. I had an ex (both of us non-binary) that really couldn’t get past that and see it for what my other friends do (the ‘tism) and only perceived as my (amab on feminizing hrt) talking over them (afab not on hrt) in a “domineering man” kind of way, even though they have way more traditionally masc traits then me (competitiveness, impatience, over confidence in their understanding of things to a point of stubbornness…). I really liked them and thought they understood because they’re also neurodivergent, but just couldn’t get over it or learn to work with it, or even give me the time to improve on it ¯\_(ツ)_/¯
Glad your friend seems to be on board!!