volocity enforces block spacing (time).
if you mine a block too early from the previous, and it's very lkikely to happen thousands of times because the diff is at minimum, it will be rejected.
yes, thats true. and in my opinion, this velocity is bad idea. hash outputs are "random", good hash can be found in 1 sec or 100 sec too. but you waste hashpower if you try to find a block within spacing time, because that block will be rejected.