Update: I also tested with 3.3v 8MHz pro mini (328p). Response was sluggish/intermittent, even with T3.2 @24mhz. I got ReadSensorValue_Grove example to run with T3.2@96mhz by adding delay(1); before each Wire.requestFrom() in the library and at the end of the powerOn() function. No pullups other than 328p's internal pullups enabled by Wire lib.