Charger options for Lumia 950 display dock

[EFats]

I have HD-500 display dock for the Lumia 950 but lost the charger. Is this just a straight up USB-C PD charger or is there something special? I tried several chargers and no luck.
USB-C

• USB-C charger from HP tablet, this has more than enough current and charges my 950 just fine but when I plug it into the dock, the LED just flashes red
• iPad charger (with regular USB-C cable) doesn't work
• BlackBerry USB chargers, I've got 2 different ones. Both "work" in the sense that the LED turns red and then goes white when I plug in my 950 but then I get the popup saying that the charger is incorrect and I need to use the AC-100 charger. I'm hoping this is just due to insufficient current capacity.

Please don't tell me Microsoft did something special with the power plug on this thing. Is there any alternative chargers that work with the dock, or do I have to find an AC-100U somewhere? I would've assumed any USB charger capable of 3A should work fine. It's not a special USB-C power cable that is required, is it?

 

[EFats]

So after a bit of digging around, it turns out there is a bit of a design flaw with the continuum dock. It is NOT fully compliant to USB standards. If you use a fully compliant USB-PD charger and cable, it will actually not power on at all. You could try digging around and try various non-compliant chargers and see if they work (I understand Nintendo Switch and one Raspberry PI variant also has a similar design flaw), however, there is no guarantee.
There's not much way around it, you basically gotta scrounge around eBay for a Microsoft AC-100 charger. Once I got one of these in, the dock works no problem.