I suspect that's not far off from what Israel did, from my understanding they modified a device's at a production level, it sounds like they essentially redesigned the pager.
It will be interesting to see how they did it with the radios.
I feel like a broken record reminding people that the TAO (Tailored Access Operations, now Computer Network Operations), part of the NSA, has been doing this for 20 years. Except they implant spyware instead of explosives. Probably.
You could get a new battery from a known good source (or light a couple on fire to make sure they're not explosive). It should be relatively easy to check the rest of the components for anything near a dangerous amount of explosive, and the body can be replaced with a custom one and/or subjected to the fire test.
Even a fire test may not produce accurate results (see C4). Better to not have distinct supply lines from the civilian population you're already hiding in.
I don’t know why you think this will be an isolated event, a civilian you probably don’t have anything to worry about in the same way you don’t need to worry about getting poisoned or shot but this is now an attack method governments will take advantage of.
It's interesting who we call terrorists and who we don't. If an Arab nation or organization had done this it would have been called a terrorist attack. Israel does it and people defend it.
Terrorist is a meaningless scare word for "people we don't like".
We read on the news 'Hezbollah pagers' and assume that this was a targeted attack. But are we sure? What does it even mean? Who and how got those devices?