If Felix Conrad is correct and there is such a thing as a core gender it would help to explain a lot. This core would be independent of chromosomes, hormones and genitalia at birth. It would help explain why very young children gravitate towards gender behaviour before being influenced by external forces.
What typically then happens is that they are dissuaded from behaving in opposite ways to expectation by well-meaning parents.
This governing core would be instinctive, need not be 100% male or female but then could be retrained via social conditioning. By means of embarrassment and ridicule you could get the child to suppress and move away from their core gender. This would also mean that Harry Benjamin could have been correct in assuming predetermination at birth.
What then would happen is that by puberty sexual orientation would begin to also play a role with gynephilics suppressing due to the inconsistency between identity and sexual attraction and androphilics aligning; thus helping to explain early onset versus late onset.
I believe strongly in such an idea and I was one of those children who gravitated naturally towards girl things and play until told to stop. The internalized shame was so strong it damaged my psyche for many years to come.
It would be hard to prove the existence of a gender core since its creation could involve a series of events tied to biological predisposition and even fortified via family situation, birth order and dynamics.
I wouldn’t hold my breath waiting for solid proof but the concept certainly makes sense.