TB 91 printing and selection
I have TB 91.9.0 x64. With previous TB versions, I could multi-select several emails in the inbox and print them all. It was as if I opened and printed them one at a time. This was a great time saver since often I needed to print only the first page of each email. To print 10 emails this way used to be 8 key/mouse steps total. With TB 91, it takes 80 interaction steps.
Printing a folder list is one thing and printing email content another. A gui either supports multiple selection or it does not. TB 91 is a big step backwards in this area. I'm ok with the design of the print options dialog. I'm not ok with losing multi-selection and departure from the interaction model of selecting items then starting a function on those items.
Alla svar (1)
I suppose you mean TB 91.1.0. There is a bug report about it here https://bugzilla.mozilla.org/show_bug.cgi?id=1727107 that has since been marked as resolved/fixed and closed. In the upcoming update 91.1.1's release notes, it is stated Printing messages that are not currently displayed is no longer supported, including printing multiple messages at once. In that upcoming update, printing of a message will be enabled only when a single message is selected and displayed. This prevents scenarios such as the one discussed in the bug report here https://bugzilla.mozilla.org/show_bug.cgi?id=1726779.
If this functionality is critically important to your use case, I'm afraid you may have to downgrade to an older version. I doubt there will be plans to implement and re-enable that feature in future releases.