Thank you @ThomDietrich and @watou for your helpful insights.
watou, I found this statement at the end of the second CalDAV link you provided, which appears to provide a workaround;
Apr 5: “So as a workaround for OH2 you can specify the full config qualifier in caldavio.cfg.”
Based on your other notes about my.openhab/IFTTT as a plausible fallback, I’m going to migrate now while there is nothing of substance (yet) to change.
Thom, I had the 1.8.3 demo up and running, but you’ve convince me to take the leap to 2.0. I’ve downloaded OH2 and have proceeded with the steps outlined in the migration procedure, not yet able to bring up the 2.0 Portal, but I’ll bring that up on the migration thread.
Again, thanks to you both for your help.