I wouldn't recommend using a grinder made out of pla for weed. The friction from grinding up the weed could potentially heat up the pla to a certain degree and you'll end up getting plastic bits in your weed and smoking it.
The very least the plastic will be grinding together. creating microplastics that you're smoking.
Thank you very much for your wisdom, professor of pot smoking🤓
No, but seriously, it is partly true that you should be careful not to contaminate your precious broccoli.