I can confirm the Dell WD19TB dock works on my Batch 6 i5 unit, but for some reason I am unable to POST with the dock connected. I need to wait until at least GRUB is visible before I can connect, after which everything will work as intended. I have not tried the latest BIOS yet, nor have I confirmed if it’s a BIOS setting that I need to disable. I’ll see if I can investigate further. A handful of other issues are OS (Ubuntu 21.04) level ones, including an unknown program crash when I reconnect the dock and the occasional shuffling of active audio devices at random moments.
In the meantime, I have the dock almost fully loaded with an Ethernet connection, two displays (one HDMI, one DisplayPort), a USB hub for my 6+ total peripherals including an external hard drive, a headset, and a Lightning cable to connect my iPhone.