I had some time to look more into it.
My guess is that the Empty CG Position %MAC needs first to be set at empty weight, perhaps this has already been calculated in the aircraft’s specs sheet? It’s literally the design of the aircraft itself that gives us this empty CG component. Didn’t remark at all that the AC has any type of ballast. I can assume that getting this set properly first would then allow for more accurate weight & balance and loading. This is adjustable in the sim with a slider but it’s kind of goofy when you think about it because this value is associated with the design of the aircraft and is like the equivalent of redesigning it physically in real time, like literally removing seats or shortening/lengthening the fuselage and cabin. 
Perhaps it is Asobos way of a type of workaround due to limitations on designing or faults in flight dynamics modeling? Maybe both. Though surely the cabin can be modeled/placed relative to camber and chord.
Now in terms of default weights, what I gathered is that this AC has an MTOW of 1,000 Lbs. The default MTOW when loading into the sim is 1,322 Lbs. That’s over 300 Lbs MTOW. I have read that there are XL models with slats and some modding that get MTOW up to 1,322 Lbs but what you have designed here is the Savannah S Not an Ss or XL. But we can perhaps see that some numbers got mixed up and implemented between models because the default numbers are just that, the 600 Kg or 1,322 Lbs. That is for a modified XL Model, not even the Ss with is slightly less than the XL but still a bit more MTOW than the standard S.
Now, in the following screenshot you can see how this affects the CG. Now, for a 240 Lbs Pilot and Copilot, that’s really pushing it. I’ve read comments from pilots who remarked a nose heavy characteristic, wishing they weighed less then 80 Kg because of this nose heavy characteristic. So, 108 Kg up front two times is really pushing it. No offense to any heavier guys or gals.
Now, when you put an average weight of, for example, 175 Lbs which is 80 Kg, this then exposes more of what is going on here, you can see how drastically the CG changes by removing weight plus 40 Lbs of baggage. With more of a norm in weight, CG shouldn’t be this far forward.
And to counter this, you have to redesign/reconfigure the aircraft with the empty CG slider to get it back into norms. And then it’s probably a lot closer to the actual aircraft’s empty CG.
This definitely does make it fly more how it should, however, getting it close to exact to the real aircraft is hit and miss, you’d have to play around a bit with weight and empty cg slider.
