A question. Just looking at Essential in M3.1 for working out what needs to be done purposes and noticed that some of the FontAwesome icons on the navigation block were not showing. Found https://github.com/moodle/moodle/blob/MOODLE_31_STABLE/blocks/navigation/styles.css#L15-L16 and thought 'odd', looked at https://www.w3.org/TR/wai-aria/states_and_properties#aria-hidden and it states 'all users' thus instead of 'true' for icon fonts then should be 'false', however this has been the recommendation: https://www.filamentgroup.com/lab/bulletproof_icon_fonts.html.
So what to do? I'm not sure!