@ Dave,
Alas - apparent, "senior moment" invaded your closing sentence. (Or - pesky Com-Ed bill exceeded grace period - dimmed your usual, incandescent analysis...)
Poster provides little "proper" justification for any form, floating point. (i.e. requirement is precisely described as, "huge!") Stand by the belief that such demonstrated "imprecision" signals similar in the code type/architecture phase. Thus it may well prove that: fast, resource-lite, scaled integer may be adequate for such, "Gov't Work..."