It's been a while since I played around with the code, but when I was, I managed to find some old original EMU data that CRush did, that pushed the range out to 1,024m. That was found to be not accurate with the original game, so it was brought back to what it is now.
If you want to have a play with the survey skill mod and survey tool range, have a look at SurveyToolImplementation.cpp
You might have to create a skill tape, or enable surveying skill tapes to bump the skill level up, or just edit the ranges for current level, although that might induce other errors.