I got dell laitude 7270 model and recently purchased the D3100 (DisplayLink) docking station. I believe it used the USB 3.0 to connect the laptop to the dock
I got two external Dell screens (normal wide screen with max 1920x1286 resolution not 4K screen)
We experience laggy, delay when using mouse and keyboard. It does not matter if cord/cordless or plug in directly to laptop or to docking station
Using laptop by itself dont have that problem
It prove to me the limitation of USB 3.0 bandwidth create this issue
Not too sure if Dell is aware of it and make any improvement. I have chat with ProSupport but so far only recommendation is to upgrade laptop to latest firmware
Please click on link below. Hopefully it will be a help to you.
Support for Dell USB3.0 dock D3100 | Dell US