the twin-pool design.

I love this idea.
Under these circumstances, one could also introduce a voting system independent of the Stake. If a vote is a vote and the payout comes from a kind of pool in which the vests are first "stored" and then converted to the number of votes actually present, there is really no need to discuss selfvotes any more. Then you have your one vote, but its shares are divided among all producers who also have a vote.

Since I am not a coder and have no idea at all whether my ideas could be programmed even rudimentarily, I have held back with it so far.