Special (and secured) storage option for 2FA backup codes / recovery codes

I have a number of sites that have 2FA enabled, and that provide a list of one time use backup codes in case the 2FA devide is lost. I would like to have a mechanism to store them in Bitwarden, but with additional security beyond just being logged into Bitwarden. The attributes I’d like are:

  • stored with the corresponding login
  • should be in a note format, i.e. multiline
  • should require at least a master password reprompt
  • possibly could be encrypted with a 2nd password

I tried Secure Notes for this, but the content is visible in Firefox extension without a reprompt.

I tried a hidden field in the corresponding login entry (i.e. backup codes for google stored with the google login), but the field is only hidden. I can select password reprompt, but that applies to the whole login entry.

Note: I updated the title to better reflect the request.
(before, it was “2FA backup code storage”)