Writing this on the #librem5 connected to the #nexdock360. Primary display is the nexdock, secondary the l5. This seems to be a lot more stable.
Had an update on the l5 (#pureos) and during reboot I could enter the pin for disk decryption on the nexdock and the nexdock showed a librem5 logo.
When the l5 entered screen lock the nexdock got disconnected and the terminal running on the nexdock screen got closed - which I didn't expect.
Btw, the #nexdock360 has got a function key to disable the big touch pad. I can't type on that thing without moving the cursor, so I disable the touchpad when starting to type.
Sadly the #librem14 hasn't got this function key (as far as I know) and I had to disable the touchpad using the xinput command. I use a mouse with the librem14 anyway.
But a pre-configured hotkey to fill this gap would be a nice thing to have.