Hey,
yes the ore deposits get richer in ore. You basically get the amount that shows on the wall with a perfect mining.
Hmm it should be accurate and I did not had the effect you discribed once. So hart to tell. :/ But I think Ill overhaul it a litte, after the jam, so Ill look into it, thanks! That includes your remark on the fail (you are not the first, that would had liked for it to go on. :) )