// — Obtain all updates, distinct by (scid, direction), ordered by seen DESC
// — From those updates, select distinct by (scid), ordered by seen ASC (to obtain the older one per direction)
let reminder_threshold_timestamp = SystemTime::now().checked_sub(config::CHANNEL_REMINDER_AGE).unwrap();
// — Obtain all updates, distinct by (scid, direction), ordered by seen DESC
// — From those updates, select distinct by (scid), ordered by seen ASC (to obtain the older one per direction)
let reminder_threshold_timestamp = SystemTime::now().checked_sub(config::CHANNEL_REMINDER_AGE).unwrap();