You can't optimize what you don't measure.
Today, in the Buildless Console, Cache Reporting features have just gone live. If you log into your tenant, you should see charts like the following:
Browsing to the Analytics section will reveal more metrics, with both daily and hourly breakdowns:
Analytics in Buildless are calculated directly from API logs, which we keep for easy diagnostics. You can access your own API logs, by the way!
Telemetry data is rolled up and recalculated every 15 minutes, weather permitting (queues can fail, etc). The system tries to keep data less stale than one hour at all times.