Great that you bring this up again.
I presume a dynamic Origin for the displayengine should solve this. It could recalculate everything based on the cameratarget whenever the target is moved x units from previous calculation, or just use the boundingbox center of all visible objects. If moving the objects solves the issue then moving the origin would too. Subtracting say 20.000.0000 units from X and 30.000.000 from Y can be done on the fly, for any calculation, without messing with the floating numbers, so it should be solvable quite easily. The job would be to find the solution that requires the least reprogramming of other tools. With so many architects using Rhino I strongly recommend you solve this as soon as you start working on V6.
And then add a dynamic grid and you have solved two decade old wishes in one go 