Had some 'fun' mining copper the other day and got confirmed that you need to clear at least 2 meters away from copper nodes and break the ground connection before the copper breaks down. Due to the size of bounding boxes it may be more than 2 meters visually, but it was very satisfying to finally get the big chunk to 'explode' in a predictable manner.

It was suggested, and there's a few videos on what people have done in the past, that one burrow under and into a copper deposit to make a safe place to harvest the ore. Did the dynamics change in the game, or am I doing something wrong? I've dug down, but when I hit up on the ore breaking it, it opens at the top, leaving me vulnerable again.

Yes, but typically there is about (on average) 10% of the deposit that is underneath the 8m dig limit.

Yes and no. The mechanic still exists, but it's not so easy to exploit. Simply having visual separation between node and ground isn't enough, since any of the chunk bounding boxes could still be intersecting something and you'd never know it, and if any chunk is still bound, then the whole deposit is still bound.

then ♥♥♥♥ ahaha thx for the help guys

Copper is sometimes tough to break in large pieces, it seems to be magically tied to something. Silver is awesome to dig around and break in two hits.

The trick us much easier to do with silver than copper.

One thing that I have found that helps this is to "crack" the floating section. Meaning hit it at least once in each "triangle section" to reduce the hp it has. Then when clearing some of the floaters they will break and fall.