As for the MAX17501's soft start capacitor, its value should be:
CSS ≥ 6 x Coutput x VOUT
If the output capacitor is increased with the CSS value at its default state, the device will be shut down. Hence selection of a correct soft start capacitor value is critical.
The MAX17501EVKIT can be turned on with a resistive load connected to the output during start up.
Electronic load can add additional output capacitance which could impact turn on time of the device and the device would fail to operate with the electronic load turned on.