Have a systemd process not run during installation

I am creating a custom Ubuntu ISO that once installed runs a kiosk program.

My issue is that the Kiosk program launches and can be seen while Ubuntu is still installing.

My idea is to edit the systemd file and add a requires= category and specify a process that runs during normal system operation but not during installation. I'd like to know a process that does that, or another method of preventing a systemd process from launching during installation.