Unfortunately, I couldn't find this information anywhere at the manufacturer's or on the web in general. With a bit of luck, someone else will answer your question.
I can't recommend the support. Just hang up the phone while talking. My PC works quietly again when I disconnect it completely from the power supply. Unfortunately, this doesn't help permanently, but it's always better than the noise.
On other pages there is talk of two monitors and, as you have already seen, the device only has 1x VGA and 1x HDMI. Ergo, a maximum of two are possible.