@Victor_S 

thank you for the very useful info and background. I naively thought that any Matter Certified device would meet the entire spec.

To be fair to TP-LInk they have already agreed to "fix" 2 out of 3 of the issues I highlighted and are evaluating whether they will implement the third (OTA over Matter software upgrades).

However, there will always be features that individual manufacturers have that are not part of the Matter spec (these are handled in Matter via what are called "Custom Clusters" or sometimes by other methods). 

An example of this is the LED dimming calibration that you mentioned.  Right now I do not see that in the Matter Cluster Spec.  Other products allow tap sequences on their dimmers to calibrate this without using an App.

A logical way forward in my mind would be to allown the Tapo App to be used to initially configure the parameters that are not supported by Matter and then allow the switch to be removed from the Tapo App without reseting its parameters back to default (right now removing a switch from the App resets all of its parameters to default), 

This approach would allow a middle ground while the spec catches up or TP-Link adds "Custiom Clusters" to its Matter code (support for which could then be added to Home Assistant and the like by Community developers).