@BrianPistone 

Kasa dimmer calibration sets the minimum light level, not max level.

However, you can use the Preset feature to adjust the brightness to a different level to avoid 100% brightness. 

  @BrianPistone 

Yes, that's an option in the Tapo App. If a 4W light bulb is still too bright for you, we suggest considering a lower-wattage non-dimmable bulb. Alternatively, you can opt to use a lampshade to physically reduce its brightness.