.. one qualification to Old Smokey's (we must have a beer at some stage .. I would be very surprised if we haven't known each other in previous lives ..) comments ..
Australia no longer views POH demonstrated values as limits, unless the value is qualified to indicate that it is a limit. Provided that a test program is done in the same way as would apply for the NAA of origin, there is no reason why a demonstrated crosswind POH reference cannot be increased for local operations in Australia. If the test crew assesses the handling as being a bit limiting, then one would expect to see a suitable qualification in the POH amendment.
Both in Oz and the US, the operating regulatory provisions covering reckless/dangerous piloting provide a constraint on ad hoc pilot extension of the demonstrated values ...
One should consider that, for most operations, a POH crosswind value of, say, 20 kt is not going to be operationally constraining .. and, for most pilots, the problems associated with limiting crosswind operations are never experienced .. and it can be interesting for the stick and rudder side of things when one has full rudder on during the final approach.