I'm fairly certain that isn't actually working like you think it is. I guarantee bench testing it at the stock DME 300Hz would only give a very narrow WGDC control range. The stock solenoids can be re-plumbed for traditional "pressure" operation instead of vac too, doesn't mean they are any good for higher boost levels. They crack open, leak, bleed pressure.
Native 3-port MAC control is coming to MHD.
Nice feature add on MHD. I'm hoping they've just found the table for the PWM output frequency to the WG so that other tuners can follow suit easily.
I'll have the tools and equipment soon to be able to measure the effective passband of the solenoid at the stock DME frequency and at say, 30 Hz. I've got a few others around, including a MAC, that I can measure, too. I've read another post where someone did the same thing, but it didn't include that Pierburg, I don't think.
I searched for solenoid that would specifically work at 300 Hz. I found reference to the Pierburg being spec'd to work specifically for OEM 300 Hz PWM. That said, the Motec and Syvecs guys use it at 30 Hz, so... We'll see with actual measurements.