Resolution not the same between different units of measure

When defining say the position or size of an object, it is always shown to 3 decimal places no matter the units. This becomes problematic when trying to be precise but using larger units of measure. For example for something that is anywhere from 0.001 to 0.130px will show as 0.001 inches (roundoff error). So trying to use inches when being very precise doesn't work very well. Infact entering more than three decimal places does not even work. I think the problem lies in the fact that the resolution of the input boxes is not the same as the precision of inkscape. Another consequence of this problem is shown in Bug #1075793.

The clunky workaround to be more precise when working with inches is to convert it to something like mm or px and enter that.

I think the proper way to handle it would be to put enough trailing zeros to satisfy a standard uniform resolution between all the units. Obviously this would not be so pretty with many 0's when using meters or feet, but there could be an option for either setting the number of decimal places a fixed number (currently 3) or a specific resolution.

Just a note on resolution/precision/accuracy and significant figures. From my understanding the resolution is the ability to resolve a measurement (ie the number of possible significant figures on the readout, in our case the H/W/X/Y input boxes) while the precision relates to the ability to read a meaningful value about the measurement (so in our case anything reading upto what Inkscape defines for the document under Preferences -> SVG output -> numeric precision). So for the most part they happen to be the same for our purposes. [The accuracy is how close the measurement is the real value, but in our case is perfect or not really applicable since we are defining all our measurements].
The point I want to make is that I think the precision between units is not the same for the same number of decimal places. For example clearly 1.325in has higher precision than 1.33in however although 1.33in and 33.66mm have the same number of decimal places, they would not have the same level of precision since mm is a finer (more precise) unit of measure. More extreme example would be units of km does not have the same level of precision as units of mm since they are on different scales by 6 orders of magnitude. To have the same precision for 1mm, the resolution for km would have to be down to 0.000001.

Alternatively, a related idea would be to have thou/mil as a finer unit of measure for imperial (see Bug #1479671)

Possibly related bugs such as ones with rounding errors:
Bug #1076428
Bug #1421392
Bug #210145

Using Inkscape 0.48.5 r10040 on Ubuntu 14.10