Technically, nothing prevents including multiple outputs in a coinbase transaction. Bitcoin and its derivatives have no protocol restriction limiting the number of recipients in that first block transaction. Yet the vast majority of mining pools operate with deferred payment systems like PPLNS or PPS. Why?
The technical reason: scaling thousands of outputs per block
A large pool can have tens of thousands of active miners at any given time. Including one output per miner in the coinbase could generate a transaction of hundreds of kilobytes, or even more at very large scale, consuming a significant fraction of the available block space. In Bitcoin, the block weight limit is 4 million weight units. A coinbase with 10,000 P2PKH outputs would occupy approximately 340 KB without counting the rest of the block's transactions, reducing the room available for user transactions. That represents a direct economic cost: the pool would lose those transaction fees.
The economic reason: liquidity and business model
Deferred payment pools act as financial intermediaries. They accumulate rewards from many blocks, calculate proportions according to the chosen distribution scheme (PPLNS, PPS, FPPS), and then make payments from a centralised wallet. This allows them to operate with greater fee efficiency (they can batch payments), adjust distributions retroactively, and in some cases retain a float that generates operational liquidity.
What is split coinbase good for then?
Split coinbase is efficient and clean when the number of recipients is small and fixed. The ideal case is solo mining: there is exactly one miner per block. The coinbase needs only two outputs: the pool fee and the miner's reward. No share calculation, no proportional distribution, no deferred payments. The protocol does the work.
For shared pools at industrial scale, split coinbase is not practical. For solo mining, it is the most direct and verifiable option available.
If you want to see this difference in practice, read our coinbase transaction explainer and review how OwnBlock structures direct payout when a block is found.