Yes, it runs constantly with no clever control strategy. The pressure regulator on the fuel rail adjusts the pressure by bleeding off whatever fuel it doesn't need. Pretty much everything pre-FSI works like this. I would expect the pump load to be fairly constant since its pushing against a constant load of 4 bar. The regulator will adjust flow between the rail or the return.
The C5 RS6 is the only port-injection engine I know of with a PWM-controlled fuel pump. It uses the stock C5 in-tank pump as a lift pump and then has a high-performance pump in-line on the way to the engine.
FSI engines seem to use this PWM method pretty much across the board as far as I know.
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