North Korea's unusual ballistic-missile submarine

Why is North Korea's ballistic-missile submarine program discussed less than other nuclear deterrent fleets?

Its technology is unconventional and opaque, but the diesel missile submarine is still serious enough that several navies likely track it closely at sea.

North Korean military technology is unconventional and difficult to assess. Its diesel ballistic-missile submarine is an especially unusual combination, but awkward engineering does not make the platform harmless. Several countries likely dedicate submarines to tracking it whenever it deploys. Technical elegance and threat value are separate questions, and an ungainly platform can still demand substantial surveillance effort.