Many poskim hold you do get an aveira. Some poskim hold it is treif.
This is true. Cholov Akum or Bishul Akum creates Tarfus in pots, for example. If Cholov HaCompanies is Cholov Akum, it creates the same Tarfus.
Don’t be shocked, you would Kasher a Milchig spoon that you put into your chicken soup by mistake.
There are Poskim who do not hold by O-U Star-K or other mass market hashghcha and only want their people to eat their own approved hashchas, does that make the mass market hashgchas treif
Chitim B’Seorim. Notice the word “want”. This is a Takanas Chazal, not some Rabbi’s “want”.