Why on earth would somebody register with a MEDICAL facility using the wrong biological sex? That's just asking for trouble. Ill-health related to being female doesn't spare you just because you have transitioned and now consider yourself male, so it's the one place where a transman really really needs to be biologically accurate.
Informing medical staff that you are male when you are not is wasting their time, and putting yourself at risk.
Presenting at a practice looking [somewhat, anyway] like a man and stating that you are biologically female must be difficult, but surely that's something that a woman thinks long and hard about before she transitions - how am I going to deal with tricky situations like registering with a GP, using women's toilets, joining women-only groups, etc.?
But if a transman asks for a smear tests and is told 'But they are only necessary for women!' and the transman replies 'I was born female and still have a cervix, so yes I need a smear test', they are not going to be turned away.
It's not like the male transwoman in France demanding to be treated by a gynaecologist, is it?
edited because I got my transmen mixed up with my transwomen🙄