Agreed on the median. My guess is that most of the gain on our card comes from Q4_K_M fitting entirely on the GPU while Q8_0 has to leave part of its layers on the CPU, so on a GPU with more memory I would expect the gap to shrink. If you run the same comparison on other hardware, I would be glad to see the numbers, especially the 95th percentile.
One correction to how I put the clarification idea: with our model the question is written before the candidate ids, so an app cannot skip it. The model itself would have to emit a short or empty question. We could test that without retraining by limiting that field with a grammar, the same kind we already use for tool names and object ids, but we have not tried it yet.