There's an option in File/Preferences called "Format FDS file for easy reading". When that box is un-checked you tend to see number written out very long scientific notation:
0.0 -> "0.0000000E000"
And when it is checked, you tend to see a nicer version:
0.0 -> "0.00"
Does this help? In general, it's difficult to find a one-size-fits-all number formatter. Something we've developed in our PetraSim software, but have not yet integrated with PyroSim is a smart fixed-width formatter that will produce a n-character string (e.g. 8 characters = " 0.0") that contains optimal precision and, if no additional precision is needed, optimizes the remaining characters for readability. If we were to integrate this into PyroSim, the option might instead be, "FDS Input Sig. Digits: [ 5]" (where you would edit the five). Would that be more helpful?