I am trying the Open Google Calendar add-on, and it’s great so far except I would like to see upcoming events on the ‘Today Pane’ on the email tab. Is that possible? thanks!
You could email the author using the address on that page. (It appears that he is French; in my experience you are more likely to get a response if you email in French, even it that’s just a Google translation. It’s just politeness.)
But I note that the addon has not been updated to TB68 so an enhancement request is unlikely to be a priority. Good luck.