I wouldn't trust any performance projections from Flitestar because they come from a generic POH for the type. To use these accurately, one would need to do performance measurements. For example FS assumes 12GPH for my TB20 but in reality I get the target IAS or TAS at 11GPH, by going to LOP.
Actually I constructed my own model in FS for my aircraft for everything including the W&B and it is dead accurate. More than a thousand hours of comparisons to prove it.