Base setup:
Adding a dialog, which extends an existing one (see print screen)

Problem 1 - Dialog is below all others:
Step1: Adding a wrong value to the extends property makes the dialog unusable (that is correct yet). All other dialogs are still usable as they should.
Step2: Changing the wrong value back to the correct value used before -> all registered dialogs are lost! No dialog is available anymore provided by this module.

Behavior on correct reconfiguration:
All dialogs of the module are lost, no matter on which location the dialog was registered.
Only a restart of the server registers the dialogs again.

Problem 2 - Dialog is places in between:
Step1: Adding a wrong value to the extends property makes the dialog unusable (that is correct yet). All dialogs placed below this wrong dialog are not registered anymore (same as on templates).

What should be changed:
That all dialogs are always registered and usable, except the one which has a wrong configuration.