Forward-compatible coinbase locktimes for BIP-54

[b10c]

One of the four requirement of BIP-54 (Consensus Cleanup) is that:

The coinbase transaction’s nLockTime field must be set to the height of the block minus 1 and its nSequence field must not be equal to 0xffffffff.

Additionally, the BIP encourages:

mining pools to update their software to craft coinbase transactions that are forward-compatible with the changes proposed in this BIP.

I’ve set up a mainnet-observer chart for this: BIP-54 Coinbase Locktime set - but it seems as of writing no pool sets their coinbase locktime to be forward-compatible with BIP-54.

Additionally, it’s interesting to look at the pools that set their coinbase locktime to a non-zero value, which might reveal incompatibilities. This is done in Coinbase Locktime set.

Querying the mainnet-observer database revealed that currently, F2Pool is setting locktimes of their coinbase transactions, and pools like MaraPool and Poolin did so historically.

Relevant discussions:

• https://groups.google.com/g/bitcoinminingdev/c/jlqlNHHNSNk/m/RBT_LBWQAgAJ
• https://groups.google.com/g/bitcoindev/c/6TTlDwP2OQg