"readonly" query param doesn't work in Analytics

Right now query has an option called "readonly" which makes sure that a sent request is idempotent (i.e. cannot be INSERT INTO, create index, etc...). If this flag is enabled, the client can draw much stronger conclusions at runtime (i.e. can reschedule a query even in-flight on the socket since it can be sure it is idempotent).

It would be great if analytics had the same. I know that right now it only supports SELECT, but in the future it might support more and also it has DDL APIs which would also not be readonly right now.