Thank you for contacting Plugable. I would be happy to provide additional information regarding our products.
Unfortunately, our USB switches are not compatible with USB-C/Thunderbolt 3/4 devices, and Plugable does not offer a USB-C “A/B” switch that allows for a USB-C/Thunderbolt device (like your Dell WD19) to be toggled between computers.
This kind of device is possible to create but is very technically complex to implement. While the there are existing USB-C KVMs like from companies like Sabrent or IOGear, these devices only obtain a USB-C input, then just switch the display signal and USB. They do not switch USB-C signal itself, which means that they wouldn’t work 100% through USB-C docks.
Sorry to be the bearer of disappointing news, but hopefully this information was helpful.