Visible traces are a bit of a misnomer. There's an injection site for the adhesive neutralizer. While it could be argued to look like wear and tear to the naked eye at a quick glance, the valuations of these coins have now exceeded normal circulation parameters and certainly require authentication.

Closer examination is generally conducted by microscope under such circumstances. Perforations cannot be hidden. Even with attempting to fuse the plastic together, it'll warp and the structure will be visible in the right wave lengths. Traces of this adhesive removal chemical will also be detectable.

You may find this thread interesting. I understand why you may feel there's cause for alarm, but the amount of experts involved today reduce the risk.

As with normal numismatics, fakes have existed for millennia. Genuine coins are still identified and generally don't lose their value even with this risk.

As with anything valuable, the sellers provenance is important... and so is forensic verification.

Here's the thread you may find interesting.

https://bitcointalk.org/index.php?topic=3257048.200

I hope this helps you feel less concerned about the risks.