During local iOS source verification on this Mac, public AVFoundation extractor verifies actual media frames and rejects static footage exceeded its unchanged 20000ms subprocess bound while generating the software H.264 dense-late fixture (15013 64x64 frames). The full iOS run reported 390 pass, 1 fail; the generator was terminated by SIGTERM at 20013ms, without stderr. Its preceding sparse/moving/late fixtures completed in 232/248/200ms. No extractor output or native-viewer acceptance was claimed for the failed attempt.
The same source’s preceding full run passed (dense-late 2237ms). One deliberately separate isolated diagnostic after the failed run passed all seven video tests, with dense-late generation taking 5713ms. This establishes intermittent fixture generation, not a fix or a performance root cause. The machine was also building the independent timed-input host; resource contention is an inference and is not established by the current diagnostics.
Instrument encoder progress and completion/error states and retain those diagnostics across the existing owned subprocess deadline. Determine whether the software AVAssetWriter pipeline stops making progress or is merely starved, then fix the demonstrated cause at source. Keep all 15013 original sample timestamps, immutable pixel buffers, explicit software H.264, exact source PTS checks and the twenty-second command cap. Do not increase deadlines or retry until green.
Related source verification: https://github.com/craft-native/craft/issues/446; LSU release acceptance: https://github.com/stacksjs/hq.training/issues/318. Logs are retained in the local task evidence as lsu148-timed-final-ios.log and lsu148-held-video-controlled-diagnostic.log.