All objects can be instantly mined by hand
Providing the player with new tools or adjusting the game interface, without fundamentally changing gameplay.
Changes to the player's in-game appearance.
New Ores and resources as well as machines.
Cause memory overflow... If you change mining time for ore and place miner on it, you basically trying to instantly mine the whole patch in time less than a tick of the game ... For each tile simultaneously... Your mod cannot work at all :D