I’m having a minor obsession with digital potentiometers!
The next I’ve tested is the MCP4017T-104E/LT (100kΩ rheostat version).
It comes in a very small SC70 package and works as advertised.
Although conveniently controlled with I²C, there doesn’t appear to be any way of setting the address.
That and the fact that it is only rated for 2.5mA make it a bit limited in scope of application.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub