Hello.
As from the OEM side (be that Boeing, Airbus, Bombarider, Embraer or anybody else) if you're given any time constraint it is up to the airline to follow it.
If the CAA declares that the time limit on the part can be extended then they take full responsibility. Otherwise you absolutely need to consult the OEM on extension.
I would have a big problem to fly an a/c that has, for example, an extended inspection interval on an ALI defined by local CAA contrary to OEMs requirements.
Cheers,