I still think your plan overreaches to an extent... however, its getting much better. a couple observations:

Curators will receive approximately the same reward that they do today, the percentage will go from 25% down to 15% but all accounts above 250MV won't curate which is why the curation rewards won't actually go down.

If you used these numbers, curator rewards would actually go way up for the non-whales who remained in curation. Right now, whales dominate curation. The people with <250MV who currently earn money from curation probably don't get more than 10% of the 25% allocated for it (or a total of 2.5 percent).

Just a quick glance at 2-17's curation rewards 5500SP out of a possible 13,750 in curation rewards, go to the top 10 curators (all with >750MV). about 6800 out of a possible 13750, or nearly 50% go to the top curators with 500MV or more.

So just taking them out of play would double the curation rewards for the people remaining.

And even those numbers are somewhat underestimated. Because some of the 13750 is lost to the reverse auction.

Jesta estimated something like 32% of curation rewards are lost to the reverse auction, which means that we should really be looking at the above numbers as a percentage of 9350. So the top 500MV and above curators are actually taking something like 72% of existing curation rewards.

Which means that if you cut them out, the remaining rewards earners would be making just more than 3.5 times more given the same percentage. Alternatively, if you cut 25% curation rewards (as a percentage) by 72% (to make them 7 percent total) current <500Mv curators would expect to earn the same amount.

Using your 250MV cutoff, its something like 7300/9350 78% of curation rewards currently go to >250mv curators. The current 22% of 25% the <250mv curators get now would be around what they would get splitting up a 5.5% without whale competition.

This, of course, doesn't take into account whales breaking up their accounts to curate rather than earn SP passively.