Potentially easy way to sort for eggs?
Just praise them for their masculine traits, and see how they respond.
Separately, praise them for traits that might be stereotypically considered feminine, and gauge their reaction.
Compare and contrast.
I stg most people will tell you their truth if you’re actually open to receiving the answer.
At one point, all of us were eggs. Hopefully none of us were purposefully deceptive or manipulative while in repression, but looking back over my pre-transition life there were SO many tells if people would have actually been open minded and paying attention.
Edit: it seems we don’t share a common understanding of what “egg” implies. My understanding of the term is trans individual who hasn’t openly espoused their gender yet, whether because closeted or as yet unaware.