Knowing what to flag. Not every update matters to HR. An incorrect military service record gets flagged even ten years out, since it's the one thing that blocks an instant retirement later, but HR isn't pulled in over every minor suggestion from someone who isn't close to retiring. Contextual flagging like this cut down HR's workload significantly, and a pre-defined set of dismissal reasons kept every response consistent, replacing scattered chat messages and personal emails with something structured and easy to track.
The real challenge was designing for both sides at once: employees needed something interactive and easy to understand, while HR needed rapid-action forms built to get things done, not to be lingered over.