@ernst I also amazed at how not just accurate birth time is important, but accurate longitude and lattitude (place of birth). I updated my birth place to the exact longitude and latitude of the hospital I was born at and was amazed that certain cusps changed in the vargas including the D1 (just a bit in D1).
Yes, it's very important the correct latitude and longitude. Especially when rectifying vargas. If we live 5 miles from the city center and use the city center lattitude we may be trying to get the D60 to line up with transit events and in some few cases it may not be possible to get everything aligned by changing the time because no time will work with that wrong lattitude. Or we get a time to work with that wrong coordinate but now the 5th level dasas are off a day. So for sensitive things if we can find the exact birth location and use those coordinates it can sometimes make a difference.