Small MUs are currently nearly useless, unless you cannot afford a Large one.
Double the rate of charge generation and double the charge storage limit and increase the Large MU charge use to 2.
Make the Charge use of the Small MU be 1 per calibration.
This will make the Small MU as useful as the Large one and also make tiles with 30-80 or 130-180 ore production (of a given type) more valuable.
There is a large gap between 0, 1 or 2 MUs for a given ore type on tiles today.