That helped. I guess from the documentation I thought that just adding the M5StickCPlus library would work. I have verified that some other programs do work (Display, TFT_Clock, PowerWake) with adjustments for the larger display size.
The AXP192 and I2C_Tester programs work with your changes although I left Wire.begin() at default because I was checking the bus on the Grove port and that now is working.
I did notice that on the Plus there is a small current draw on the battery (-0.5 mA) when I am running on USB power but it is 0mA on the StickC.