I've done it on hatch day. For my daughter's girl scout troop. They'd been following along with the hatch. Each week I'd bring a few eggs in an insulated lunch bag to candle with them. I set approximately 20 eggs at the same time of day as their meeting.
Because of the Girl Scout insurance policy it would have been a ton of paperwork, including background checking all drivers, to get them to my house. So I opted to drive the incubator to their meeting. Less than 10 minutes away. Plugged it in when we arrived. Chatted for a bit. Then they got to watch the hatch. This included a full zip and hatch! They thought it was amazing. Afterwards I drove it home to finish the hatch. It was a roaring success.
I don't remember the exact hatch rate but it was pretty good. These were eggs from my own flock of assorted breeds. Not sure I'd repeat this with valuable or shipped eggs. But absolutely would do it again hatching from my own flock.