I've read the very good instructions for complete Mac uninstall at https://support.1password.com/uninstall-1password/.
And I congratulate you for being one of a handful of 3rd party Mac app developers that provides much in the way of assistance.
But doesn't 1Password start automatically when you sign in to Mac? I'm not 100% sure, because I admit I have so far only been experimenting in a Windows VM, but actually the main reason I haven't been testing in Mojave is precisely because most Mac applications, once installed, leave pieces of themselves behind forever. Very often tons of pieces. Most harmless, but messy. And some of them leaving some components permanently running - even if you run their provided "uninstaller." So I almost never install anything without a very good reason.
So my question is, if it starts up automatically, I don't see anything in the uninstall steps that would remove it from whichever of the many plists Mac uses to launch programs at startup. It doesn't seem likely to me that macOS would hunt through the various ~/Library folders to see if it should launch something.
Maybe it just doesn't matter? Maybe if Mac can't start a program, it just ignores it? Or even (if it's a good idea) permanently remove it from whatever plist the program is configured in?
If 1Password just inserts itself as a user "Login item", I can erase that easily enough from System Preferences > Users & Groups. Most of my automatically starting apps don't launch from there, but it's true they have to start earlier (A/V, firewall, online backup).
I read in some thread here at the forum that 1Password is launched when you start Safari - so it would be the extension that starts it up. But that thread is old. Could a Mac app extension also do that? But then when would the 1Password mini button get into the menubar? And what if I just wanted to consult any Secure Notes or IDs etc. without launching my browser? Hanging startup off the browser sounds like it would apply to1Password X, which probably isn't compatible with Safari.
Thanks for reading my essay!
1Password Version: Not Provided
Extension Version: Not Provided
OS Version: macOS 10.14.6
Sync Type: 1Password sync