I suggest you to use MM setting for this high output MC cart FIRST in case you will overload your system!!! MC setting with 60dB gain is way too much for an 1.6mV output cart!!!
About which capacitance value is the best? It'd be hard to tell as this is rather system dependent. Basically, the higher the capacitance value, the more likely to trigger off peaking of certain high frequency resonance of the carts. For example, for your Tube Box SE, if the maximum 440pf MM setting sounds harsh or bright or sharp, try lower the capacitance value until you feel satisfied. It would be hard to tell by anyone else who don't know nothing about your system.