You know something that I just realized? Considering that thanks to Patton, UN forces were able to push into North Korea a lot quicker, the levels and intensity of bombing campaign against the country would likely not have been as heavy compared to OTL, in which an estimated 85% of the country's buildings were razed.
Meaning that the northern parts of Korea will retain a lot more of their colonial-era infrastructure that were set up by the Japanese. Take the Sup'ung Dam that I have mentioned from earlier, for example, with it being the largest hydroelectric dam in Asia at the time, which in OTL was not targeted for bombing until May 1953
(As a reminder, we are still in November 1950 right now). This means that unless the Chinese managed to push the UN all the way back to the 38 parallel, in addition to holding onto much more land and control a larger population, the ROK should be able to industrialize much quicker and easier, given them a much stronger economy and higher standards of living depending on how quickly the government in Seoul can get their corruption problem under control, and secure countries that they can export to.
The idea of there being a much earlier
Miracle on the Han River right on the PRC and the USSR's doorstep will certainly have some very interesting implications on how the rest of the Cold War would develop. Especially in the case of the former, assuming the famine caused by the Great Leap Forward still happens.
And as a lover of history, I really like the idea of cities in northern Korea beyond just Kaesong managing to retain their historical buildings without having to be rebuilt almost totally from the ground-up.