Harvesting nodes as a reward
I thought this is already the case, but just not 100% of the time.
I know for example there is an ettin cave in queensdale guarded by a veteran ettins and a lot of ettins. Inside the cave there is a rich copper vein and several small ones.
I have seen rich nodes outside these guarded places, but those seem to be be placed randomly throughout the world (and change always).
Some thought provoking quote
There are actually places in Orr with 5 or 6 trees but monsters all around. So this has happened before, but they can’t do it on all of them due to the randomization of nodes. I like some of one and some of another to be honest.