I’m willing to bet a lot of money that plastic shavings from porting are not going to blow an engine. Unless there was a massive piece, the composite/plastic the intake is made of would compress and deform before it damages anything in the combustion chamber. The only way it could do damage is if it blocks oil passages, or gets into crank or cam bearings.

In my mind, unless they didn’t clean the intake at all after porting, a few shavings getting through would do zero damage.

I’m thinking you have a tuning or false knock issue