I have enabled the "open links in private tab" option in FF for Android.
It's nice to have the added layer of privacy, but it means that whenever I click a link in any app, including for example a link from an email, I'm never automatically logged in any site.
It would be nice to have a quick option to exit Private Mode and return to normal browsing with the page reloaded with access to all my login cookies, similarly to how the "open in Firefox" option returns you from the simplified web view UI to the full UI.
Currently if a link to a page that requires a login is opened into private mode, the only two options are 1) log in manually each time, or 2) copy the URL, tap "open in Firefox", open a new non-private tab, paste the URL and go. Both options are cumbersome and impractical.