Hi @MacL3an we had several discussions about this topic in the past, e.g. Agreeing on optional user interface hints in templates - #3 by pablo
My opinion is to create a GUI spec on top of templates, which includes rules like the ones you mention. In many cases I don’t think the place for those rules is the template. This spec we’ve been working on covers the layout, rendering and binding of GUI elements with openEHR model elements, it doesn’t include the rules model yet https://discourse.openehr.org/uploads/short-url/5635h3NBrDHbY830w93jctgPsBM.pdf
I hope requirements like yours could speed up the elaboration of such models and the approval from openEHR.