GM has confirmed to us in tickets (twice) and I am quoting here directly from that response:
" As we stated, it is not a violation of the Code of Conduct.The fact that you claim a vein does not mean other tribes or players cannot harvest it, even on PVE servers. So be mindful of that while doing element veins."
We were also told to 'secure the vein'.
Would be happy to take requests on how you can secure a vein and be mindful in PVE (especially if you are solo) without kiting to kill anyone near the vein? Can't build on it as raiders have tek suits so they can get inside whatever you