We only recommend using the individual-recordedSexOrGender extension in the case where creating a use-case specific extension or property is not practical.

Personally I don't think that is a good idea, as it will create a mulitude of profiles / extensions (even within the US) potentially for the same use case in the absence of a corrdinatign body to facilitate this work - in V2 we specifically created a separate segment to accommodate reporting of ANY recorded Sex or Gender the same way and it would improve cross-mapping between HL7 product families, if FHIR adopts that approach as well.