To me, trans is a further extension of homosexuality
I disagree and I think this is fundamentally important. Homosexuality is about who you desire to have sex with, but the trans movement can be surprisingly homophobic.
Trans is complex. Every person is of course an individual, but there groups within the trans umbrella with different needs and desires. Young girls with rapid onset gender dysphoria are often lesbians struggling with their sexuality, some homosexual males take on an exaggerated drag type role, though this can be an extreme reaction to previously experienced homophobia. Then there are the often older males, who derive sexual satisfaction through performing womanhood, but are usually heterosexual.
It's important to understand these distinctions and know there isn't a common sexuality. And anyone proclaiming to be a trans ally really needs to understand the basics.