Analytics API: Summing tHandle/tAcw for 30-min intervals

I’m trying to pull agent utilization metrics (tHandle, tAcw, tHold) broken down by 30-minute intervals. The standard /api/v2/analytics/queues/queue/summary endpoint only gives me 15-minute buckets or hourly aggregates. I need granular 30-minute slices for a custom dashboard. Is there a specific query parameter or endpoint I’m missing? I’ve tried tweaking the date range and group-by options but nothing returns the exact interval I need. Here’s the current payload I’m sending: