I don't think we're going to agree on any points whatsoever, I'm afraid.

I think their method is pointless, that introducing new formats that are indistinguishable from well established ones is actively harmful, that their reasoning is flawed and raises mainly irrelevant points, and their only valid point is that fractions with denominator 256 are stored exactly, but then if the whole point of converting your colours to floats is to do interesting transformations of the colour space that you can't do with integers, that's all gone as soon as you start manipulating the floats, and all your carefully designed exactness went down the pan. If you want exact, keep it to the integers 0-255.

Neither[-0.5/255) nor [0,0.5/255) are some sort of disadvantaged and discriminated against group of humans that need more representation and I don't understand why on earth anyone would care even a tiny little bit if they were under represented nor why you would describe it as unfair.

The whole thing is really, genuinely deficient in benefits and has obvious drawbacks.