Unitronics is well aware of this "mistake".
Everyone who has put MF values on a display has faced this problem in UntronicsLand. I've run into the problem with competitor's HMI products as well. The nature of a IEEE floating point value is you can't easily extract the location decimal point and the number of significant for display.
True, you could theoretically create an object that could extrapolate the decimal via code. But then what would you do if the float became large or small enough that an exponent was required? What if the exponent needed to be negative?
Anyway, the Vision series has never promoted itself as a floating point powerhouse - you can tell because there are only 64 of this memory type. Unitronics will not be improving this product line's functionality significantly - the focus is on UniStream now.
I feel your pain on this and have banged my head against that wall. But the problem is still there. I would advise you to go back and revisit the algorithms using MI's or ML's, especially if displaying the output value is required.