AFAIK you already don't have to use that addon anymore since at least 78 or even earlier. Eg. my only addon in Thunderbird is "Provider for Google Calendar" so

AFAIK you already don't have to use that addon anymore since at least 78 or even earlier. Eg. my only addon in Thunderbird is "Provider for Google Calendar" so that I can sync my calendar with my Android phone other than that I've not used Lightning in forever.