Discussions here have convinced me to ask this separately.
Isp or mass-specific impulse is a ratio of thrust (force) to mass flow rate (kg/s). It comes in two flavors, seconds and meters/second depending on if it's multiplied by $g$.
Is Isp understood to be calculated using all mass flow rates including those that might be combusted to generate electrical power or mechanical power to drive turbo pumps and potentially other things?
I suppose we can ignore the kerosene used to run hydraulic systems, even though in some cases those systems are not closed!