I tried to balance the mod so it's not too overpowered. You need the ore you want to find first, so it only makes subsequent excavations a little easier/less grindy. There's a durability on the knockers too, and their range is somewhat limited (Right now it's a 32 block radius, I might make it smaller if necessary)
It still takes a bit of trial and error to find the ore, so it's also a bit gamified and doesn't tell you straight up where the ore is, so there's still some challenge involved.
This mod works best in tandem with the prospect pick, you still need that tool to find the general vicinity of the ores you want.