Prior to MDL-78324, a modal type could be registered with the registry like so:

ModalRegistry.register('block_gearup_form', ModalSaveCancel, 'block_gearup/modal_form');

This informed the registry that the core module ModalSaveCancel could be used while the template for the modal should be another one. I used the above to augment the modal forms and include a delete button in their footer.

The factory no longer respects the declaration of the template when creating the modal, despite the template being a compulsory argument when declaring a modal with the registry.