That’s probably the simplest / safest way to time each 4-miler. You can use the previous 4-mile results as the start list for the next one so you’ll just need to post a single start list.
After each 4-miler is complete:
Navigate to Home panel of the app
Click on “Race archive"
Click on “My results”
Click on last race
Click on “Use as start list”
This will copy not just the start list but also the app setup from the previous race. All you need to change is the “Race name”.