I still use GC too, but I also use pal as a backup for some event types.

I have a my.calendar text file in the cloud, which is both human- and pal- readable. But I also have a cron job that adds the clean version of the output to my daily journal file. This file is also synced via cloud storage and easy to review in a simple text editor on my phone or laptop, etc.

Just one way to do it very simply though. Good luck in your search.