cd /home/weezboo/... hard-codes a user-specific path and will break when the repo lives elsewhere (even though the systemd unit already sets WorkingDirectory). Consider switching to a configurable PROJECT_ROOT (as in other scripts) or using the script directory to resolve paths.

nan_count will likely double-count NaN/Inf events: metric_nan_count matches any occurrence of '(loss|grad_norm|eval_loss)': ... (nan|inf) anywhere in the log, including inside bad_metrics={...} on nan_guard_detected lines, and then guard_nan_count counts those same guard lines again. To keep the counter accurate, exclude nan_guard_* lines from the metric grep (or tighten the metric-line pattern so it only matches the trainer’s metric dict lines) before adding guard_nan_count.

The metric grep only matches nan|inf but not +inf / -inf, while the Python-side _is_non_finite treats those as non-finite too. If you want monitor parity with the callback, extend the pattern to include signed inf variants.

The watchdog increments nan_consecutive only when 'nan' in last_metric.lower(). Since the monitor/callback logic treats Inf as non-finite too, this misses inf, +inf, -inf events and could fail to restart on an Inf blow-up. Consider checking for both NaN and Inf (ideally with the same regex used elsewhere).

make manifest uses $(TRAIN_CONFIG) but the argument validation only checks RUN_DIR and LOG_FILE. If a user clears TRAIN_CONFIG (or runs with an empty env var), this will fail later with a less actionable argparse error. Consider validating TRAIN_CONFIG in the same check (or defaulting it explicitly for this target).