In general I agree with other responders, in that it is best to let them explain their bigotry. Having said that, and for the record:

• a stealth trans woman will face misogynist discrimination at work
• a non-stealth trans woman will face transmisogynist discrimination at work
• a stealth trans man might be able to take advantage of passing privilege and male privilege combined ^[1]
• a non-stealth trans man will face transphobic and misogynist discrimination at work

If any of the above people are non heteronormative they will face homophobic discrimination either way.

Let alone that these legal transition procedures are wildly imperfect, and it would be unreasonable to assume that a person can as easily transition in law as they imply. In fact it might take years and $$ just to get just the most important paperwork done^[2]. And then what? Do they think that legal name change is like a Permanent Polyjuice Filter that allows you perfectly pass and live as the other gender?? P r e p o s t e r o u s

Besides, why would anyone transition in paper if they are not transgender? This is the most basic comeback. Ask them “Why don’t you switch genders then? Grass might be greener on the other side.^[3]” They will probably respond “But I am not trans”. “Neither am I”, continue, “I just want equality at work, trans rights included”.

(Source: Old social studies coursework on transgender issues, but some info might be outdated.)

This

These are chemicals found in every single human, how can you think they cause insanity? Also environmental stressors play a big role on mental health issues, but what you call “insanity” might be better defined as neurotransmitter imbalance, and it has not a lot to do with sex hormones, but a totally different set of chemicals.