hey @lavande. thanks for checking in!
We have developed the contract extension as decribed in the original post and have a pending pull request here - contracts-bedrock: extend the l1block contract to store historical block hash data by vladimir-trifonov · Pull Request #6903 · ethereum-optimism/optimism · GitHub. After some back and forth, addressing comments etc. - our work should be considered done, pending implementation / merging by the Optimism development team.
Once it’s implemented, the L1 block contract extension should be ready to be leveraged by builders in the Optimism ecosystem.
Appreciate the RetroPGF shout out. Once we see measurable impact from our efforts, we’ll make sure to apply!
Thanks!