Clipboard managers have internal functions that tells them not to remember stuff copied from certain sources, which is the behaviour we'd want from whatever comes out of password managers.

Unfortunately, the copied text coming out of the ProtonPass web browser extension (at least on Firefox) is plain text and my clipboard manager remembers it forever in its memory, which is not ideal for security. (I'm using Pasteboard Viewer to check the type of text that is stored in the clipboard.)

Apparently, there is a way to tag text as sensitive from browser extensions: this was reported in an issue on the repository of a clipboard manager (https://github.com/p0deje/Maccy/issues/561), and its developer suggested the browser extension developer to implement http://nspasteboard.org/ standards. Once the extension developers properly tag the copied text from a password manager extension, Maccy will recognize it and handle it approprietly.

It would be great if this could be implement in ProtonPass.