A mod like this (I personally use auto-chart), is still useful for slower computer rigs because the built-in preview does terrain first and ores second and this process takes much longer than just heading right into the map with this sort of mod to make an quick assessment (I've have timed both ways and the time difference is like night and day).
IF, however, the built-in preview had an option to do ores first and terrain second, that would be awesome because I care less about terrain than I do the relative positioning of ores.
~B