I would like to propose implementing XIP-1898 for xdc blockchain.
XIP-1898 forks from EIP-1898 which add
blockHash option to JSON-RPC methods that currently support defaultBlock parameter.
My draft XIP will be availabled at https://github.com/XDC-Community/XIPs.github.io/pull/14. Comments on the pull request are welcome and if you have any questions, we can discuss here on xdc.dev or https://github.com/XDC-Community/XIPs.github.io.