Is recommended to use expiremental http status codes in my rest api

As I asked upon:
https://softwareengineering.stackexchange.com/q/436150/249660

I am thinking to use 402 status code for methods that require payment in order to be proceeded. But as I see in RFC 2616 is reserved for future use. Also, MDN states that this response code is expiremental: https://developer.mozilla.org/en-US/docs/Web/HTTP/Status#client_error_responses

So if I use it for methods that require payment, what complication I may have in the long term?
Should I adopt in my API or wait in order to be actually used and not reserved for future use?