According to the official blog post, Nethermind and Flashbots proposed a Rollups-based PBS proposal "Alternate PBS" that allows the MEV revenue generated based on Rollups to be captured by Rollup itself, rather than by preferential payment to the proposer of the ordering chain. Alternate PBS also solves another issue related to stealing Rollup blocks. Without careful construction, the proposer of the ordering chain can observe the base Rollups blocks constructed by unsuccessful Rollups builders and rebuild these blocks for themselves. This allows the ordering chain proposer to receive the value of the building block without the cost of building (just copying) it.