You can't set alerts on the secondary WAN connection. It would really suck to be paying for a secondary WAN connection only to not notice that it went down for a long time without you noticing it.
I agree, I had this happen recently for a customer. Needless to say they were very upset. I used the (make a wish) to request this alert be added. I'm not sure why the delay, the code would be very similar to the primary link failure code so they should have already implemented it.
Customer support service by UserEcho