TYPO3 Core

Szenario:
- Create form in backend
- improve settings in yaml config file
- include form on page in backend and use the option "Override finisher settings"

For example, i set the subject for MailToAdmin in my yaml file but need other email-addresses on each system.
Now i get an error on sending this mail, because i did not set the subject in override settings.

I think there should be a test for this. If i set an override so take this value, but if not, so take this value from yaml config.