A recent Huberman podcast with Matt Walker covered a few good strategies for coffee consumption. I think it was that podcast where it was suggested you should

A recent Huberman podcast with Matt Walker covered a few good strategies for coffee consumption. I think it was that podcast where it was suggested you should start your day with a dose of morning sunlight (dropping your cortisol levels); have your first coffee around mid-morning and your last sometime around midday. The 8-10 hours you mention is actually the half-life of caffeine for the average person - the point where the level in your system has dropped 50%. I would also debate whether caffeine/coffee consumption should be classified as an addiction, simply from the fact that it is not necessarily self-destructive and doesn't cause long-term harm or permanent changes to the brain.