I don't think so ...

Of course you are right! How time sometimes can blur the memory ... It's much more logical that the delegation "return delay" has been adapted to the post rewards window than reversed. :)

I wonder if curation rewards should solely depend on the weight of the upvote? So that neither the date of the upvote nor the number and strength of upvotes of other users would influence the curation rewards of a curator (but only his HP and the percentage of the upvote).
I know that would make self-votes on comments etc. more interesting again, however, at least for the author it would still be more beneficial to get more upvotes than only his own self-vote.
So as curve for the author rewards we could stick with convergent linear, but for curation rewards the simple formula that curation rewards would only depend on the vote weight of the curator could apply?

I know the matter is complicated and maybe my ideas have more weak points than I am aware at a first glance ...