Thanks to both @gw and @pherjung, both solutions are viable:
-
The lipstick2vnc approach worked
- I did not dare to reboot my broken device, so invoking
lipstick2vnc
directly as a defaultuser via ssh did the trick - edge swipes were almost impossible
- interaction was very laggy (client: tigervnc)
- remote keyboard input probably works (didn’t check)
- I did not dare to reboot my broken device, so invoking
-
Screencast app via web browser + USB mouse
- this is the approach I adopted in the end to export data from some Android apps
- interaction still laggy, but better than via VNC
- edge swipes with mouse worked decently enough
- performance massively improved after decreasing quality settings in System settings → Screencast
- problem: attaching a mouse via USB disabled the on-screen keyboard, the system thought that a USB keyboard was connected as well (at least with my mouse)
- I was able to get on without keyboard inputs
- attaching a keyboard via a USB hub might work as well
Interaction was annoying in both cases, but I managed to get out all the data I wanted.