I don't know how much impact the "Design management" widget vs. "Design" object decision will have, except for the extremely small number of teams that work exactly like we do.

No one has requested it before so it's certainly not something we're planning to add.

I'm sure there will be a few other people out there who eventually want something like this, since Interactions are actually a great fit for enforcing consistency in data structures when working with a schemaless NoSQL store, but obviously it's still a bit of a niche audience.

To give a little more context, structures like this often come up in my work when dealing with NoSQL datastores, especially ones that rely heavily on JSON, like Firebase, where a records unique ID isn't part of the record itself, just a key that points to it. I think most Ruby/Rails projects tend towards use cases where these sort of datastores aren't appropriate/necessary, so it makes sense that this wouldn't come up as quickly as other structures.