Crosswind limits applying to aircraft handling are normally advisory – max demonstrated, unless flight tests show that a limit has been reached, then there should be a crosswind value in the AFM limitations section – max crosswind.
Where an engine has a handling limitation this should be published in the AFM as an engine limitation; any wind condition associated with this becomes a limit for the aircraft.
A note linking the engine and aircraft limits would be appropriate in the aircraft crosswind section.
Prudent operators would use max demonstrated as a maximum crosswind value.