community feature desire: prevent undesired extension of schema definitions

[karenetheridge]

ref. https://www.linkedin.com/posts/erikwilde_unpopular-opinion-xml-schema-was-a-better-activity-7267856239269756928-_tnU/?utm_source=share&utm_medium=member_desktop

What can we do to add functionality that will prevent a future modification to a schema definitino (via $dynamicRef) to allow things that the original definition wants to prohibit.