What is changing
Quorum selection is drawn per transaction and per round, seeded from the round number and the transaction's own identifiers. The release tightens that derivation so that two nodes independently computing the same round always agree on the selected set, including under clock skew.
Eligibility gains an explicit liveness filter. A node that has not responded within the round window is excluded from the next draw rather than being selected and timing out, which shortens the tail on transactions that previously waited for an absent validator.
What is not changing
Selection remains random and per-transaction. A fixed or long-lived validator set would read as a committee, which is the opposite of the property the mechanism exists to provide. Quorum size is unchanged.
Operator impact
No configuration change is required. Operators running with aggressive resource limits may see selection frequency drop slightly, because the liveness filter now notices slow responses that previously went unrecorded.
Nodes will log a selection-miss reason where previously they logged nothing, which makes it possible to distinguish 'not selected' from 'selected and failed to respond' for the first time.