Auto containment blocking Opera browser 1Password extension

Opera stores it’s extensions in %appdata%/roaming/etcetc but I can’t I work out where to exclude the extensions folder.

The 1Password desktop software works fine and the 1P extension isn’t blocked in Microsoft Edge.

Any suggestions gratefully received.

I’ve narrowed it down to the Auto Containment / Pseudo File Downloaders section which blocks all unknown “downloaders” in any browser.

Adding the file rating “unknown” has unblocked the 1P extension.

This needs to be added to Containment as a trusted file / process. How can I do this?