Let's say scientists have found out how to manipulate your brain, and can make a stimulated virtual environment where you can't distinguish the real thing from the virtual world. Now, here's the twist, some people have decided to apply the findings to gender-based therapy, and the purpose of the simulation is to make it easier to discriminate between those who should transition vs those who are better off not transitioning. Would you recommend this approach? Would you consider being part of the simulation?
No.
Your scenario is binary, Yes or No to transition.
Some people are sure it's what they want, get 1/2 and think, this is perfect and get off the train. That person is now better off but would have been denied with the simulator.
I would rather use that technology as an education tool for those who are unsure or want to experience the opposite gender role before starting. Let the patient make the call not the machine or an outside observer. That's a gatekeeper extreme.