According to @BitMEXResearch, its new report on The Growth of Bitcoin Merge Mining examines the prevalence of multiple OP_RETURN outputs inside BTC coinbase transactions and frames the debate over whether such data should be considered spam or legitimate merge‑mining metadata (BitMEX Research). According to the Bitcoin Developer Guide, coinbase transactions are constructed by miners, bypass mempool relay policies, and may include arbitrary data, while OP_RETURN outputs are provably unspendable and still count toward block weight (Bitcoin Developer Guide). According to BIP141, Bitcoin’s block weight is capped at 4,000,000 weight units, so additional coinbase data reduces available capacity for fee‑paying transactions and can tighten the BTC fee market during congestion (BIP141). According to Bitcoin Core policy documentation, standardness rules govern relay but not consensus validity, meaning miners can include non‑standard elements in the coinbase without violating consensus rules (Bitcoin Core policy). According to the Bitcoin Wiki’s merged mining overview, merge mining lets miners earn auxiliary‑chain rewards at little additional cost, which can influence the trade‑off between including coinbase data commitments and prioritizing fee‑paying transactions—an incentive dynamic traders should monitor when assessing near‑term BTC on‑chain fee pressure (Bitcoin Wiki: Merged Mining).