It only adds like ~5ms. Unless you have `query_level_metrics_enabled` as True which takes more time. I didn't find that particularly useful on prod and instead just used it locally when fixing stuff. Depends on what data you need populated in your callback function on prod.

The header feature can also be useful. If you have a client on-call who's complaining about super slow page loads. Just check their network tab and see which response has a query count/time header which seems unnatural.