Honestly, I'm not bothered at all.
I sincerely thought you were stressing about knowing the answer and personally don't really think anyone has a definite answer. I thought maybe you can put it to rest but I understand your reasons not to hurt your tangs.
I can point you to
@Jay Hemdal who can probably help you understand where and why this keeps coming up. I think he may have a post on it somewhere.
Here is one that popped up with the search button on the top right of your screen. It contains a link to the subject.
Thread 'Tang HLLE Carbon related?'
https://www.reef2reef.com/threads/tang-hlle-carbon-related.1036402/
Have a nice day!