I have started working on more calendar integrations now.

If you write me a short mail at info@invisible-computers.com and tell me what integration you need, I will make sure to let you know once it is out.

In the meantime, there are often ways to sync other calendars (also iCalendar) with google calendar. It’s a bit of a detour but it might just work.

For reference, here is a clunky way to sync Outlook calendar events with Google Calendar, using Microsoft Power Automate (which comes free with many Business accounts): https://jacobfilipp.com/sync-outlook-calendar-to-google-cale...

CalDAV is where the money is

You think so? More important than outlook?

If you get CalDAV working, you will support a ton of non-gmail/outlook providers for 'free' including those that are self-hosted. For e.g. runbox, mailbox.org, mailo, etc. all provide caldav to their users - some of these also support exchange but in my 'research', caldav was universal.

Yes please! CalDAV may be an overkill, iCal (which is a "read-only" protocol) would be fine for this device.

I've started working on it yesterday :)