This shows a fundamental misunderstanding of what special economic zones are in the DPRK. They are not as they are in the PRC, where they are capitalist safehavens. In the DPRK, these are zones for international trade. All industry is still publicly owned.

The DPRK does have limited private property in its Special Economic Zones. See A Capitalist in North Korea: My Seven Years in the Hermit Kingdom. Foreign investment and ownership happens there too, such as from the Emperor Group owning a casino and whatnot, a group based in Hong Kong.

This just isn’t true, though. The public sector in China is the same as the public sector in most mixed economies: Transportation, parts of agriculture, some electrical and telecomms, etc. It is no different. In fact, China has a larger private sector compared to its public sector than some of these western countries. China’s healthcare system is more privatized than most of these western countries. Your analogy with the rubber vs the ball just doesn’t apply here; China’s primary industries are all privately owned except for certain areas in agriculture. I do very much pay attention to this, because I am waiting with bated breath for it to change.

Good news, public ownership does control the large firms and key industries in China:

Your point that some western counteies have higher ratios is exactly why we need to identify the principal aspect of the Chinese economy, and not compare simple ratio. Otherwise, western economies would have far more similar results than the dramatically different results they do. The private sector in China is relegated to small and medium secondary firms, and is about half sole-proprietorships and cooperatives. On wikipedia, there is a very good point:

State-owned enterprises accounted for over 60% of China's market capitalization in 2019[4] and estimates suggest that they generated about 23-28% of China's GDP in 2017 and employ between 5% and 16% of the workforce.[5] Ninety-one (91) of these SOEs belong to the 2020 Fortune Global 500 companies.[6] Almost 867,000 enterprises have a degree of state ownership, according to Franklin Allen of Imperial College London.[7]

In other words, although the number of people employed is smaller than the private sector, and the GDP is lower, state owned enterprises still dominate the economy because they are the largest and most important. This is only looking at SOEs, too, not the rest of the public sector.

That's why I suggest that you listen more to our comrades from China, rather than assume that every socialist model has to look exactly like the USSR. China's conditions are different, and their socialist system is working well and continuing to develop to higher stages of socialist development.