an idea would be to think a new class TNonVisualControlRepository (at the same level of TDataModule), almost: TNonVisualControlRepository = class (TDataModule).
In this way as more form can share a (class or instance of) datamodule, so multiple forms could share menu, OpenDialog, and other resources via this repository.
Edit:
using a datamodule, we can already do this
(I think a new dedicated class would be easy to code)