Smartphone stuff does comply with the standards, it does not have to comply to NSI, They don't make the rules, they just inspect too the standards we all use. No idea where the 5 minutes comes from, the only requirement is to sound internal sounders for the exit duration when arming remotely, and to log who used a remote device. Previous firmware would remote arm instantly which could cause false activations if someone is still in the building. Highly unlikely in my opinion, but it could happen.
Firmware was launched last week that allows the required capability. Thing is everybody expects anything electrical they buy to have an app, whether they use it or not is a different matter. Its all part of the buying decision and not having it seems to most to be a negative.
I have been testing our system for years now, never once armed the system with my phone except during testing. I use a fob as its on the keys I will use to lock the door and open the car. Notifications are useful when i am working away, at least i know if the last one out of the house has actually armed the system.