This may help; https://support.mozilla.org/en-US/kb/use-master-password-protect-stored-logins Use a Master Password to protect stored logins and passwords

FredMcD, thanks for contributing. The article to which you refer doesn't describe a method for setting a timeout limit on the Firefox master password.

I think there was an add-on that did this. I don't know if it's available, or its name.

FredMcD, the extension was Master Password+. It's legacy so does not work with Firefox Quantum (57.0.1).

Unless the App developer update to work in FF57 older Addons will be disabled or removed.

Note that you can cancel the MP prompt to logout of the software security device.

• Options/Preferences -> Privacy & Security: Logins: "Saved Logins" -> "Show Passwords"

See also:

• Options/Preferences -> Privacy & Security -> Certificates: Security Devices

Firefox options/preferences don't include a timeout feature for the master password. That would be a very welcome addition.

Here are your choices; 1) Contact its support and ask if they will update 2) Find a replacement 3) Downgrade to a prior Firefox 4) Do without

As my original question described, I'm hoping someone can help me exercise what FredMcD described as choice #2 – find a replacement for MasterPassword+. I haven't succeeded in that search. Has someone else? I'll interpret silence as a "No."

If you want to leave feedback for Firefox developers, you can go to the Firefox Help menu and select Submit Feedback... or use this link. Your feedback gets collected by a team of people who read it and gather data about the most common issues.