It works with the IPad Pro 2018 12.9, and also with a Lenovo Thinkpad 390

Hello, my hub is connected to the usb c of my laptop without an external power supply. The hub's usb c port allows the smartphone to be charged directly when everything is connected. However, I don't have a power supply powerful enough for my laptop to know if I can also charge it from the hub's usb c port.

No. The connection is only for charging. No data transfer.

Yes, there is a jack!

The hub does not need its own power supply. I connected the charger of my laptop to the USB-C input of the hub. By the way: USB-C chargers and devices communicate with each other, so you can't break anything by using the wrong charger :)

Yes

Yes it works with Samsung Dex. I have my Galaxy S9 connected right now with an external monitor, mouse, headphones and keyboard plugged in without problems. It even charges my phone through the type-c port on the dock.

Yes, the adapter works fine with the Surface Pro 7. The cable is a bit short, so be careful not to wear out the USB-C connector. As far as I know, "HDMI without alternative mode" is about whether you can connect a screen directly using a USB-C to HDMI cable. I don't know if the SP7 supports this.

Auf die Frage nach dem nicht funktionierenden HDMI-Modus erhielt ich folgende Antwort: does your Type C jack support Display port Alternate Mode? Is it a USB 3.1 or USB 3.0 jack? Only MHL Type C ports with DPAM and USB 3.1 can give HDMI signal over the adapter. Please check in manual from notebook or with the notebook manufacturer. D.h.: Nein, wird nicht unterstützt.

Unfortunately, no information is given on the manufacturer's website.