I'm not sure if it will help with Bitwarden's functionality issue with Private Browsing mode, but if you go to the Firefox settings page, then open the Private & Security tab and then scroll to the History settings, you can find the option to make regular browsing just like Private Browsing. If you change the history setting to Use custom settings for history the Always use private browsing mode checkbox appears.

You should be able to use Never remember history to achieve the same effect. The only big thing that Firefox does in Private Browsing mode is that it erases your history and other browsing data when you close it. There's not really any other "privacy protection" when running in Private Browsing mode.

Bitwarden likely use local storage to store its logins data and this storage isn't available in Private Browsing mode.

• https://support.mozilla.org/en-US/kb/common-myths-about-private-browsing

My question is: can I get the same privacy protections in a "regular" Firefox window as in a Private Window by setting privacy protections in Options?

You can set Firefox to clear your history at the end of your session in regular windows, but there is still a difference. Private windows use memory (RAM) while regular windows use a combination of disk and RAM. So if you are deeply paranoid, regular windows with the setting to erase history from disk at shutdown are still not as private as private windows that never write to disk due to the ability of advanced forensic tools to recover deleted files or deleted data within files.

You can possibly use the portable Firefox version that by default doesn't use the disk cache.

• https://portableapps.com/apps/internet/firefox_portable
• https://portableapps.com/apps/internet/firefox-portable-esr