The BIM software application Autodesk Revit uses a similar internal representation of dimensional units and coordinates as other CAD applications (double precision real numbers - double precision real, IEEE 754) and therefore coordinates and dimensions in projects can be expressed precisely to approximately 14-15 valid digits.
When drawing or moving objects, Revit may intentionally exclude user-supplied dimension values less than about 0.8 mm (usually specified in error). This limit cannot be circumvented by numeric input, formula, scaling, or editing or importing.
Also note the conversions between inches/feet and the metric system units. And beware of numerical instability for projects far away from the 0,0 coordinate (large coordinates). The number of valid digits available to accurately represent a value is reduced by the digits "before the decimal separator" and there are fewer digits "left" for decimals. This can lead to inaccuracies, e.g. in the order of hundredths/thousands.