The answer to the weekly challnege is to introduce a "priority" parameter and make a graded OKR, e.g.:

- For prio=1 messages, latency SLO is 99.9% < 10 sec (e.g., for security SMSs)

- For prio=2 messages, latency SLO is 99% < 60 sec (e.g,. for transactional SMSs)

- For prio=3 messages, the latency SLO is 90% < 600 sec (e.g., for marketing SMSs)

In this case, PM should ensure that not all clients get themselves priority one ranks, otherwise the graded SLO loses its purpose.