If that's the case, it looks like you have sufficient amps available, since the alt output isn't dropping voltage. Just volt loss from load downstream. That's where the sense circuit alts shine. Either way, you're still fine. One wires tend to have good idle output once you get them to kick on.
Sorry if this is too elementary, but it is actually an easy to understand analog.
Think of it like fuel and a pressure regulator. One-wires are like regulating fuel pressure at the pump, but the actual pressure at the carb is whatever is left after all the drains on the system (small hose, filter, hose length, nitrous fuel solenoid, etc). A sense-circuit alt is like regulating after the carb with a return system. Everything before the regulator is at the same pressure and the excess is bled off as return fuel to the tank. as long as the pump puts out enough volume to maintain pressure, the pressure remains constant. If the demand is higher than the pump's ability to maintain that volume at that pressure, there will be no excess and the pressure will drop to a point it can maintain volume at the new pressure. Now substitute Volume with Amps, and Pressure with Volts.
Technically, it's more like a PWM fuel pressure controller with a sensor on the fuel rail, but we'll leave that alone.