We have a system that tells us when the cabin doors are closed, also when they are armed. We know when the APU inlet opens, we know where the flaps are. We even have a light that tells us when someone has locked the front toilet door.
Every car knows when a door is open - the technology exists - so why cannot we have a micro-switch that tells us when the lock on the cowl has been engaged correctly?
How long before a cowling brings one down?