In Firefox, loading unsigned extensions is severely restricted. It's a separate process to install them, and they'll only last until you restart the browser.

I'm not sure what Chrome's specific rules are; I think they allow loading local sources in dev mode, but warn you about it every time the browser launches? I generally advise people to avoid Chrome if they care about security/privacy anyway, so I've never checked in detail.

But if Chrome does have a way for you to easily load extensions from source, and you're comfortable using it as a main browser, that could be a valid way for you to tackle a problem like this.