The mentioned fix allowed for using a larger range than +/- 50.000 quants, but it does not directly affect the precision of objects that far away. Some of the changes I have made to the map compiler should improve precision though. The way it works is that a certain number of bits is used for the integer part of position and a certain amount is used for the real part of the number (before and after the ".")- if you are close to the origin almost all bits can be used for the real part. If you approach a region that's far from the origin most bits are used for the integer part and blocks become less precise.
Possible workarounds are to use terrains, MDLs with invisible collision geometry, or just draw the road on a texture on a less curved block.