Comments asserting a partner is down, being rebuilt or not yet installed are true on the day they are written and wrong afterwards, and nothing prompts anyone to revisit them. Behaviour is described generically; current state belongs in operator memory, not in tracked files.
The tab collected over SSH on every 30s poll — 8.3s a load with HOST2 down.
vv_parse_conf_scalar() captured to end of line, so a commented toggle parsed as
"true # HOST2 back online": every threshold read right because (int) stops at
the first non-digit, and 38 booleans read wrong. The Fallback tab has been
showing failover disabled while it was on.
Writing down what each endpoint actually guarantees made the places it
didn't obvious — shell arguments reaching a crontab or a bash -c
unescaped, master.conf written without tmp+rename, and conf edits that
could be saved without ever being parsed.