I would like the 2 separate questions because I could then give an honest answer. Honesty and integrity is important to me.
If a trans person chooses to answer the sex question dishonestly that's their business. I also don't believe all trans people would be dishonest. Plenty know what their biological sex is and have no reason to pretend otherwise.
Conflating gender and sex (are you male, female, transwomen, transman, non binary etc) is problematic. If I choose female, it is an identity (cis woman) I've selected, rather than factually having described my reality. I'm not cis. I fear this information is then used against me and all women as proof of our acceptance of gender theory.
It is yet another boundary over stepped by those with power. And it matters, in the same way cat calling still matters in the fight against misogyny. A small thing yes, but puts me in my place, and supports the system which keeps women dehumanised and subservient.