I'm using an older version, but have recreated on 8.8.2. If an email is converted using EmailConverter.emlToEmail, and then back again using EmailConverter.emailToEML, and the email has the Cc header ...
Since 0.105.0 and #15692 there appears to be no way to get records in a case-insensitive way if the path is a variable. I would expect to be able to add ! after ...