this is a drum that i will never stop banging.
OK if you want to add a field for gender identity, if you really think that is useful or helpful, go ahead.
But always always record sex correctly.
And this works in the TRAs favour, surely? if you can't identify, say, a transwoman, you can't identify where resources might want to be targeted to help them (as in services required/needed/desired for transgender patients at the NHS). You can identify, with actual, real numbers, how many and which categories of crimes are committed against (and by) them. etc etc.
But no. confusion has to rule the day. And this is the end result.
As pp said: Slow. Fucking. Handclap. To. The. TRAs.