Xnova motors are not then any other ESC about settings. Most default settings are just fine, but there are some things to consider.
Any setting on an ESC designated "outrunner" should not be used. Specifically, Castle Creations has added "outrunner PWM" mode. This setting may cause higher running temps on Xnova motors and SHOULD NOT be used. The default 12khz setting is recommended. Using higher PWM frequencies will result in a cooler motor and warmer ESC. So if your ESC is undersized slightly, use a lower PWM frequency to lower ESC temperatures. If the ESC is oversized relative to the motor, then a higher PWM frequency will decrease motor temperatures slightly.
Normal or low timing is ok for the Xnova motor on Castle Creation. You can experiment with your setup to see which mode produces the most efficient operation.
Additionally setup samples for Castle-Creation:
Xnova 40** series: 3 or even lower for timing and 12KHZ.
Xnova 4530-500KV-8D or 450KV-8D : 3 or 5 for timing and 12KHZ.
18* for timing ,PWM Start with 8.
P and I gain = default.
MODE 4 AUTOTIMING (remember to reset your ESC when exchanging motors-MODE 1 then MODE 4).