Yes, these preferences are stored in Google cookies.

When you say you are doing a Reset, do you mean a Firefox Reset that strips away all of your extensions? Wow, that seems a bit drastic. Have you considered using Clear Recent History instead, and not clearing the cookies?

You can manage your cookies to expire naturally by only allowing session cookies for all other sites where you don't want them to persist, but allowing persistent cookies for sites you care about.

There's no built-in way to prune away all the other Google cookies you don't care about, or to re-create a cookie between sessions. Maybe there's an add-on for that?

You will have to avoid clearing cookies from websites (domains) that have settings that you want to keep.

You can let all cookies expire when you close Firefox.

• Firefox/Tools > Options > Privacy > Cookies: Keep until: I close Firefox

Create a cookie 'allow' exception for cookies that you would like to keep.

• Firefox/Tools > Options > Privacy > Cookies: Exceptions

In case you are using "Clear history when Firefox closes":

• do not clear the Cookies
• do not clear the Site Preferences

• Tools > Options > Privacy > Firefox will: "Use custom settings for history": [X] "Clear history when Firefox closes" > Settings
• https://support.mozilla.org/kb/Clear+Recent+History

Note that clearing "Site Preferences" clears all exceptions for cookies, images, pop-up windows, software installation, passwords, and other website specific data.

Clearing cookies will remove all specified (selected) cookies including cookies with an allow exception that you would like to keep.

To keep cookies from a particular site and delete all the rest, don't delete cookies using any built-in Firefox features like Clear Recent History, and use an add-on like the following instead.

• https://addons.mozilla.org/firefox/addon/selectivecookiedelete/