I think you're over thinking it, bidbots and large investors will find a way to leverage their downvoting power efficiently and that alone will clean the house and concentrate rewards to chain beneficial initiatives.

Going to 50% curation reward will simply require much more downvotes to counter the circlejerks stacking votes on feel good content.

Vote buying won't go away with a simply more complex curved curve. Vote buying is not easily monetizable while it should be, so much so that all vote buyers eventually compete for near 0% profit as some have content they actually want to promote at a cost, some have content that will attract downvote or organic upvotes. If votes sellers are so obvious to detect they can be removed from UI views, or downvoted in a systematic manner.

I'd be interested to get on a discord call to discuss these things with you.

BTW I fully agree with your take on SPS finding