The biggest issue is that the neutral point IS that you can't change sex. It's an experiment to stop the functional of primary sexual organs and to stop the development of secondary sexual organs so that you may be able to later take drugs or have surgery to imitation the secondary sexual organs. At no point do you change sex.
This is why the language absolutely matters because the phrase 'sex change' is wholly misleading.
Ironically sentiments about being born in 'the wrong body' don't capture the point that you can't change that body but do actually acknowledge it.
If we are looking at the outcome for a study on this it would be that you successfully changed the appearance of your secondary organs with complication and have reconciled your discomfort with the sex of your body as a result and are happy.
I distance on pronouns and persistently pushing the idea you have changed sex is showing an unhealthy response to treatment. It's demonstrating there has been no reconciliation and the person is continuing to escalate. It shows a state of denial.
This is actually all really important. You can't ever be mentally resolved if you aren't at peace with your body and that's enough. It should not be relying on outside interactions and affirmation at all cost.
And there is lies the bias of the very premise that a small number of people are better changing sex.
Cos sex is not gender. Everyone knows this. Even those transgender. Their identity as being transgender even admits this.