LSB size capacity is "5.0Vh/Rsense" with 0.010 ohm in Table 6 of MAX17055 datasheet. So what would be the LSB capacity for 0.020 ohm sense resistor ?
The capacity LSB is expressed in uVh/RSense regardless of the RSense. For example, if you have a 10mOhm sense resistor:
5uVh/0.01 ohms = 500uAh -> 0.5mAh.
When your sense resistor changes, the RSense denominator changes, but the numerator LSB (uVh) remains the same. For example:
20mOhm, the equation becomes 5uVh/0.02ohms = 250uAh -> 0.25mAh.
For current, the LSB is expressed in uV/Rsense, and dividing by ohms gives you a uA or mA LSB with scaling.