As I have stated in other comments, fractional powers are extremely difficult to do using integer math and are expensive operations.
These are not multiple economic changes from our perspective. Switching to a linear curve has some drawbacks which the other parts of the proposal address.
A reservation with linear rewards is that bots will self vote their maximal voting power and humans will continue to use the site as they have and potentially not use all of their voting power. In this scenario bots will get rewarded at a faster rate then their stake. We want human users to be able to use their voting power a little quicker to help curb that effect. We gave a range of values from a small bump to a large bump and appreciate all conversations discussing the merits of those changes.
If any one of these three points does not pass consensus we will not ship the hardfork as is and go back to the drawing board. That is not us being stubborn but protecting the blockchain from exploits and threats that exist if they do not get passed.
Well, if you can do square root, you can do n^1.5 easily enough (and I guess n^0.25, etc.). n log n is also implementable without enormous difficulty, I believe (couldn't be wrong, I haven't actually implemented it and worked out all the annoying details).
I don't know what that does to curation rewards though, maybe you addressed in a different comment and I didn't see.