The only thing that’s blocking me is that my Thunderbird does not have that - maybe an installation option I turned off looong ago. This makes it troublesome for me to try and find the options.
I also asked a few people if they knew about this, but nothing came from there.
Maybe you can try setting things up in Google calendar first (seeing SuiteCRM’s calendars in Google Calendar), to see which options work, and to troubleshoot any problems, and then try to reproduce that in Thunderbird/Lightning. I suggest this because there seem to be more people using it this way, and anybody has a Gmail account where they can try…