Completed both events, went smoothly and was a ton of fun.
During workout #1 multiple prompts for the upcoming group ride event began popping up on the companion app about 30 minutes in which was slightly annoying. I dismissed all of them.
Once I completed the full 60 minutes of workout #1 there was about 30 seconds left on the group ride auto join prompt. To be safe I ended and saved the ride instead, logged back in, and late joined the group ride event by just a few seconds. I joined just as everyone was rolling away and completed the event with no issues.
Both rides synced with my Strava and I was credited for them on Zwift.