My apologies - I mis-read your first post. So the numbers you quoted were the pressure loss over time?
Your reference to ‘tweaking the cylinders’ confused me. Don’t you mean moving the pistons up or down the cylinder from TDC? If so, the difference in pressure loss is associated with leakage past the piston rings.
I’m not sure that a leak test of that type by positively pressurising the cylinders will identify a head gasket fault which is causing ‘steaming’ when the engine is hot. Steam is generated by water entering the combustion chamber under negative pressure via faulty gasket / head-to-block seal.
Quite often, a faulty head gasket sealing problem allows coolant in to the combustion chamber after engine shut down where the static coolant pressure increases in the head due to latent heat after the water pump ceases operation to circulate coolant through the radiator to keep it cool. Since, unlike when the engine is running, there is no longer any pressure in the combustion chamber to counter the pressure outside in the coolant passages any defect in the head-to-block sealing will allow coolant to seep in the the cylinders.
When you next crank the engine that coolant is forced out of the exhaust valve to settle in the exhaust pipe/silencer and when that gets hot you see steam emerging behind the car.