They shouldn't be able to undergo either procedure. No one under the age of 18 should be able to get married or be subject to human experimentation (ie puberty blockers, hormones) or trans surgeries.

If there's an epidemic of 12 year olds getting married then its very immoral to focus on supporting human experimentation on kids instead of fighting child marriage. That would be like responding to an FGM epidemic by using it to argue for child soldiering.

Your stance amounts to asking people to choose between different ideologically motivated forms of child abuse instead of opposing all child abuse. This is as demented as NAMBLA pretending its either them or pedo priests.