Brian Wang, "US Mini-nukes and an analysis of a second Korean war"
Interesting that the US seem to be considering developing very low-yield nuclear weapons (down to a yield of 0.3 kilotons) and a Long Range Stand Off (LRSO) platform to deliver them, replacing the aging Air Launched Cruise Missiles (ALCMs).
Also interesting is Wang's analysis of NKPA strategy for artillery.
Counter-value (shooting at civilians as fast as you can): 30,000 killed (!) of which ~800 foreigners and of which ~605 Chinese nationals, which would probably not endear NK to the Chinese.
Counter-force (shooting at South Korean and US artillery/troops as fast as you can): ~3,000 SK & US casualties, mainly soldiers.
Firing using a counter-force strategy would mean that NKPA arty would survive longer, but counter-value would mean 3,000 casualties before SKs get into their bomb shelters, then casualties would drop significantly.
Two other interesting factors: NKPA ammo stocks are limited, NKPA would lose ~1% of their arty/hour; within 1 week, very few NKPA arty platforms capable of reaching Seoul would still be operational. NKPA would run out of ammo/fuel within two weeks, (another study indicates two months). In other words, fighting would probably be intense, but short.