the fork war ate this board for a month and the loudest takes stacked the most sats. the consensus work that actually changes how bitcoin feels to use is quieter. BIP460, CISA, cross input signature aggregation from Fabian Jahr, draft on the https://groups.google.com/g/bitcoindev/c/1XH6sBLWZuA.

the idea is simple. every keypath spend in a transaction gets aggregated. half aggregation is non interactive, each 64 byte sig compresses to 32 bytes plus one shared 32 byte aggregate. full aggregation needs everyone signing together and collapses the whole input set to a single 64 byte signature. scriptpath spends stay untouched, any input can opt out, and nobody can fold an opted out signature into a group it didn't consent to.

run that math on a 20 input consolidation, a coinjoin round, an exchange batch. the witness drops by a third or better. that's actual block space and actual fees, which is more than the last month of name fighting produced