Yeah, Process Explorer seems to be essential to remove an external drive.
I get the $metadata processes constantly. Which is another reason why I suspected AVAST as what was locking my hard drives, because when I disable the AVAST shields, the $metadata processes DON’T come back after I cancel them.

If you don’t disable AVAST shields (and even “stop” the AVAST service), the $metadata processes will continuously come back about 30 seconds after you stop them with Process Explorer.

And once I stop AVAST, and those $metadata processes stop, THAT is when I can get my hard drives safely removed. Which is why I don’t think this is a Seagate problem but an Avast problem.

I know tons of people have had this problem before, so like I said, I’ll keep testing it and see what routine gets things done, with the least about of interruption.
(I would try disabling the root kit scan outright, but other people have already tested that and said it doesn’t work.)

~~And yes I am doing the “safely remove” thing. I close windows explorer (where you can right-click and “eject”) just in case that is what is locking my drives (it never is, but I want to tie off all possibilities).