Today I received the AENZR docking station from Quarnero.
I got excellent results. I tested it with 5 different power supplies and got 3 times 5V 2A negotiated and measured in all 3 cases above 1A consumption.
I get 5V 2A with:
- Power bank when using USB-A to USB-C. (when using USB-C to USB-C with the same power bank I get 5V 0,5A)
- With the power supply of Raspberry Pi 4.
- With a Samsung smartphone charger 5V 2A USB-A to USB-C.
I get 5V 0,5 A with:
- Sony smartphone charger 5V 3A 9V 2A 12V 1,5A.
- The original Librem 5 charger.
So we have a pattern here. The 2 newer and more high tech power supplies deliver worse performance than the good old USB-A to USB-C when having an USB-Hub/Docking station of this class in between the charger and Librem 5.
As a last test before clicking on the reply button, I decided to use the Librem 5 power supply with a small USB-C to USB-A adapter and USB-A to USB-C cable to the docking station. And wow 5V 2A. 
The idea behind is, that if you are on the go, you might not want to carry several different power supplies with you. This way a tiny adapter and a second cable are sufficient and you can go with the Librem 5 power supply.