It seems that rather than just being the default, anything not in DefaultCombatantFields is unavailable to GetCombatants (e.g. TargetID, CP and GP). Expected behavior would be for, as the name would imply, DefaultCombatantFields to be a default, but it seems to be acting as both a default and a whitelist (see MiniParseEventSource.cs:336).
It seems that rather than just being the default, anything not in DefaultCombatantFields is unavailable to GetCombatants (e.g. TargetID, CP and GP). Expected behavior would be for, as the name would imply, DefaultCombatantFields to be a default, but it seems to be acting as both a default and a whitelist (see MiniParseEventSource.cs:336).