<blockquote>
The unfair advantage of n^2 is the same if the SP is in a person’s one or several accounts all voting for the same content.
</blockquote>
<p>
True, but at least such a whale would have to spread his Steem power on many different accounts, so that every single account had less steem power - also the ones executing the last upvotes in the row. Apart from that he would have to own quite some accounts to profit from the n^2 effect ...
</p>
<p>
I <em>still</em> think either a <a href="https://en.wikipedia.org/wiki/Sigmoid_function">sigmoid</a> reward curve or a curve which <a href="https://steemit.com/steemit/@jaki01/conciliation-of-the-reward-curves-die-versoehnung-der-reward-kurven">starts as n^2 and ends linear</a> are at least worth to think about ...
</p>