Hey Felipe,
We are working on integrating 1Password X with the 1Password 7 desktop app. Once that is done, you will be able to edit logins without opening a new tab. This feature is currently in beta on our Mac version so you can try it right now if you’d like. You can find the instructions here: https://support.1password.com/getting-started-1password-x/#to-integrate-with-1password-for-mac