Here’s the setup on the app:
Start type = Mass
Record lap times = On
Number of laps = 2
Customize lap names = On
Lap 1 = Checkpoint
Lap 2 - Finish
Timing mode = Multi-device splits
Device #1 records = Start, Finish
Device #2 records = Checkpoint
After sharing the final start list to device #2, you’d navigate back to “Hardware Setup” on device #2 and set “Chip timing = Off”.
You can have a 3rd device that records just the Start, but it should be easy enough to start the race on the same device that’s recording the chip finish. You can do this from the finish line by being on the phone with the volunteer starting the race - or use “Race clock adjustment” to start the race on the finish device at some later time once you know when the race got underway.