Function mtp_catchup_enabled 

pub fn mtp_catchup_enabled() -> bool

Drafter catch-up feed on serial->speculative transitions (ATLAS_MTP_CATCHUP=1, staged off). During serial-decode stretches the scheduler rings the per-step final hiddens; on the next propose the gap rows are batch-fed into the drafter KV so it never runs stale. Wrong feeds cannot corrupt output (verification rejects bad drafts) — the stake is acceptance only, which is the flip gate’s metric. Force-off in multi-seq MTP mode (single-sequence ring; see mtp_multi_seq_mode).