I'm writing a story where a young man raised in a devout Conservative family risks suicidal odds to rescue an Orthodox girl who fell onto the subway tracks hurting her ankle, who is about to be crushed within the minute by a subway train. Heaven grants them both the luck they need. The girl is persuaded by this young man's action that he is 'righteous', of superior innate moral character, so she consents to meet with him further and eventually introduces him to how much more beautiful Orthodoxy can be.
Does Orthodoxy allow for "up-conversion"?
Are the mamzerut issues on the boy's side cancelled out by his new birth as an Orthodox regardless of any prior ancestry that he has?
Since the boy has existing training does he still need to study for a year, or is some of the training abbreviated by what he already knows?