In New Zealand you cannot contract out of state legislation. It's illegal to discriminate on age here so, with possibly very few exceptions, any age limits in a contract would be null and void.
Everyone is a legal expert all of a sudden...
Which jurisdiction applies in the case on contract law?
https://www.claytonutz.com/knowledge...tion-agreement
https://en.wikipedia.org/wiki/Conflict_of_contract_laws