The examples here currently default to hardware I2C with commented-out code for CPX, software I2C and hardware SPI.

It would be relatively simple enough to default to "CPX or hardware I2C":

if hasattr(board, 'ACCELEROMETER_SCL'):
    i2c = busio.I2C(board.ACCELEROMETER_SCL, board.ACCELEROMETER_SDA)
else:
    i2c = busio.I2C(board.SCL, board.SDA)
lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c, address=0x19)

This way the two most likely scenarios will Just Work™

(it would obviously need better documentation too)