Yes, I understand what you are saying. But let’s walk through this in specifics on how it might work. It get’s complicated in practice.
Units are easy. What units is it in, what unit would you like to go to. DWG and DXF are the worst, because technically they do not have units, so guessing is the only way. There are many hints and we try to use those when we can.
Transforming the geometry is not bad. What is complicated is how to specify it. Take the facade model. How would you want that process to go? The original position of that facade is drawn at an odd angle. How do you specify the new origin point? How do you specify the new X axis and the new Z axis? There must be 3 points. There is no telling if that is a North, West or South facing facade?
Oh yeah, there are lots of worms in the can. But to simplify the discussion, let’s take this example we already have.