I just checked my X3s (delivered in May, 2021) and they have FA251 model.  Does that mean I have the 250 watt amp?  Gosh, it seems weird we all would have different model amps, clipping or not.  I hope Clayton will address this so we all can relax.
Edit:  I went to the Hypex website and can confirm FA251 is 250 watts and FA501 is 500 watts.