chain.rlp incompatible with post-merge-only clients

Since https://github.com/ethereum/execution-apis/pull/627, tests/forkenv.json uses a pre-merge genesis with staggered fork blocks. This means chain.rlp contains pre-London and pre-merge POW blocks.

Clients that only support post-merge networks cannot import this chain.

Before #627, the genesis used TTD=131072 equal to genesis difficulty, meaning the merge happened at genesis and all blocks were post-merge. That chain was importable by any post-merge client.

Would it be possible to revert the genesis/forkenv to use an all-post-merge configuration (TTD equal to genesis difficulty, all forks active from block 0)?

This concerns the EL client ethrex, which only supports post-merge blocks