Is it easy to revert from version 78 to a previous version?

Hello,

I would like to get off version 78 as it lacks the ability to save encrypted emails in decrypted format (which I could do with the Enigmail plug-in and a filter). Thus, I can no longer search encrypted emails that have been saved.

Version 78 also lacks the ability to export the email messages to an mbox.

Version 78 also no longer has the folder view switcher add-on I was using.

Additionally, in dark mode, version 78 has some white on white text in dialogs (font dialog is one example).

Thanks in advance.

This, from support.mozilla.org, refers to TB 68 but still looks relevant: https://support.mozilla.org/en-US/kb/unable-launch-older-version-profile#thunderbird:linux:tb78