Can you imagine digging through your votes to see how much % each one is actually giving to the author? "Oh man I got a $20 upvote from @famous_whale! Oh, it's 100% curation :-(". Not exactly the experience that would drive users to the site IMO.
I think that this is partly a User Interface problem to solve. It could be made into quite a positive thing. If @ famous_whale gives me $20 at 100% curation and @ MrGenerous gives me $5 at 50% curation then the interface could show:
Visibility $25 Rewards $2.50
with a breakdown of:
famous_whale Visibility $20 Rewards $0
MrGenerous Visibility $2.50 Rewards $2.50
With visibility determining my position on trending etc. Both visibility and rewards measures could be seen as positive to new users.
Of course it would be a big change to what we have now, so a shock for existing users. But I think that something needs to change fairly drastically on the content side of Steem.
The top ROI strategy would be to simply automatically vote with 100% for posts that are approaching payout time. You wouldn't even need to consume RC's making your own comments.
I don't think that there are any ROI strategies, unless I've missed something. Oh, are you talking time value of money over seven days? Pretty small beer I think?
From a standard user perspective, you would just feel used to get such votes that don't give you anything.
If blocktrades, or another whale, were to upvote my post for $50, but only give me 10% author rewards, or even 0%, then I would be happy with that. As long as it got me $50 of visibility on the post payout then it has value. With more visibility more people would see my post. Some of those readers might give me a percentage of their upvote too. Some might just give me more visibility. Advertising / sponsorship follow and then the big time.
You can already allocate your voting power to pay yourself if you like.
You can. But such practices damage Steem by making trending a nonsense and failing to promote great content. I think that we need solutions to get great content onto trending and get the best Steem content creators out there.