mini-gauges are gauges that are parts of other gauges right?
the floating point representation could be relitive to the size of the parent gauge.
or you know I just thought of something, why not have at the top of the table a $X_scale_division_factor: and a $Y_scale_division_factor:, it divides any numbers parsed by that, you can put 1024 and 768 in respectively and anything you put in will be the pixel space for the 1024X768 display mode, internaly the code handels it as a floating point, divides the table value by the division factors to get the 0 to 1 value then multiplies it by the current screen resolution to get the actual pixel position, you can store the floating (0 to 1) representation for maybe a later in game resolution switch.
if you were to put in 1 and 1 for both division factors then the values entered would be the 0 to 1 system, if you put in 100 for both it would be percentages.