Premise #1: Crown sinks (in moderation) are good and useful things to have, particularly if they are not the sort of thing that upsets people much.
Premise #2: The current state of affairs, where a small number of wealthy individuals can seriously manipulate the prices in the energy markets without real cost to themselves by herding other buyers/sellers with offer walls is regrettable, and low-cost solutions to this would be worthwhile
Given these two premises, I would suggest two changes.