I do have some concrete suggestions, but I'm afraid they may not be terribly popular at the moment. Several of them are complete or partial reversions of past changes.
I think the vesting schedule should be much longer so that stakeholders are tied more effectively to the long term consequences of their decisions. It was shortened to the current schedule to appeal to a wider group of "investors", many of whom I think are destroying long term value with their shortsighted and reckless behavior.
I also think we should return to non-linear rewards. Perhaps not the original R^2 curve, but at least an R^1.2 curve. The point is that there needs to be incentive for consensus, rather than simply a zero-sum competition for rewards as linear rewards give us.
Additionally, I think there should be curation rewards for downvotes as well as for upvotes, and curation penalties for upvoting content that the rest of the community downvotes into the negatives.
All of these changes should be considered together rather than individually, and are designed to encourage responsible voting focused on the long term value of the network.
R^1.2 curve would probably work. Actually been benefited from the current HF19, maybe I woumd stay on Steemit till now because of that linear rewards, but yep, that’s also what all these happened ever since.
Downvote curation is absolutely necessary, since except for a flagging war, we tend to treat our downvotes quite cautiously, even on the « disagreement with the reward » side.