Relationship: read-only contact fields

Created an MR that uses the Read-only Field Widget → module. Not sure I'm crazy about my approach.

Your solution is more aesthetic.

I am hesitant to add a dependency unless necessary.

I agree. Should we enforce it with validation too (e.g. to prevent ECA actions from doing things they shouldn't)?

Form validation, or entity validation? We could add form validation

I am hesitant to add entity validation until we have a contact merger feature.
When merging two contacts, how do we update the entity reference fields? Do we use the entity api and save a new revision, or do we update the database tables, including revision tables, directly, and invalidate the contact tags?

I would assume that entity validation would be the only way to prevent ECA actions from being naughty.

I see the challenge with merging. IIRC there's a way to bypass entity constraints. If that's the case (do you know?), I think entity validation is the way to go.

I think entity validation is the correct solution. I am learning toward direct database updates when merging contacts.

Why direct? Wouldn't that restrict CRM to SQL backends?