Feature summary (what you would like to be able to do and where): I would like administrators to be able to ping more than 50 users, similar to how they can submit API requests larger than 500.
Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution): Certain messages that are larger than 50 users, but are more specific than a mass message.
Benefits (why should this be implemented?): See above.