First of all the PractiScore 1.x scoring apps are discontinued. See PractiScore 2 apps.
Currently there are no scoring options that allow enter scores for multiple competitors at the same time. Your best bet is to use a small paper scorecard for a stage. Mark hits on it and at the end of the stage enter them into the app.
We may consider adding better support for Clay sports in the PractiScore 2 apps.