Your security profile needs to exceed that set for the highest level of clearance you could possibly gain. In practice that means exceeding the highest level of security used in an organisation. You wouldn't want to inadvertently exfiltrate a clients data would you? Aside from that, it is not uncommon for say a department to not be aware they are being pen-tested with consent of their management, and you don't want to trigger counter measures.

I upvoted you because your first sentence is a useful observation, but I'm having a hard time using any of that to justify throwing away a wifi adapter. Even if it were possible to fingerprint the adapter beyond its MAC address, there's no global database of whitehat pentester wifi adapter fingerprints, and such a thing would be worthless anyway. You're not going trigger countermeasures by reusing a wifi adapter. The only threat model that remotely makes sense for that kind of precaution is fear of nation-state level resources trying to identify and catch you. And that's well outside of the realm of "pentesting".

(And the idea of accidentally exfiltrating data through a reused wifi adapter is ludicrous)