I am not happy. This machine as a stand-alone is great but has it's issues when connected to a lot of peripherals like external monitors and a bunch of USB devices.
Today I tried the second dock to get working but failed again. This dock was promising as natively two 4k displays could be connected. I only have two 1080p displays right now but even with those it was a pain.
Connected with everything the CPU percentage of the kernel_task went up to 800%. I read about it and this is the way macOS avoids overheating of the CPU. I don't understand it, the machine didn't do anything. The GPU should be able to drive two 4k displays with ease. But everything failed. My Logitech mouse and keyword lost connection all the time, everything was laggy. Once disconnected from the dock, the machine was chilling again.
This beast should idle all the time but something is wrong.
The fan control is also very strange. Once both of them ran on max level and even when the CPU/GPU load is done, the fans still spin on max level. I installed Macs Fan Control to monitor the temperature and to control the fan speed. This machine has 6 cores with sensors. I use 1 and 2 to control it. Without this piece of software the fans go crazy and they don't stop. Something is completely wrong again, Apple - please fix this!
Overall this machine only is fun without any external peripherals - which is not the use case I have. I will continue to test with 2 USB-C docks this weekend to drive my monitors directly via HDMI. The Logitech devices are now connected via Bluetooth and not with the Unify dongle - much better (I never thought I will say that).