@jebeck on waiting for "subType", I understand the feeling of wanting to wait for it to actually be an issue before doing something.  I'd just like to add some points/questions rooted from my own experience to the discussion and if you still want to wait, then we will wait.

1. What is the code difference right now on your end between checking for `subType === 'extended'` and `extended === true`?
2. What will the code look like when/if we add subType later and you have to support both formats (even if we do a migration of the data format, the migration will happen as (a) write code that handles both, (b) deploy code, (c) rewrite old data to new format, so backwards compatible code will have to be written)
3. 95% of boolean "flag" columns I've seen in a database have been deprecated and replaced with a "tag" column instead