If invalid properties are passed to QQmlComponent::createWithInitialProperties or QQmlComponent::setInitialProperties, QQmlComponent goes into the error state and is impossible to use again. See the attached testcase.

Those properties are set for a single instance, so I wouldn't expect them to break the component.

A workaround is to reach into QQmlComponentPrivate and clear the errors after that happens:

QQmlComponentPrivate::get(component)->state.errors.clear();