It’s been a little less than a month since Firefox 90 landed with FTP support completely removed, and now Firefox 91 is already here with various improvements and bug fixes, including the simplified printing feature for a clutter-free print preview page (available under More settings > Format > Simplified in the Print Preview dialog). However, it should be noted that this feature doesn’t work on all pages.
Firefox 91 also improves the HTTPS-First policy for Private Browsing windows, allowing them to make all connections to a website secure (HTTPS), as well as to fall back to insecure (HTTP) connections only when a website doesn’t support secure connections.