Could there have been advantages to extending an invitation to North Korea to observe the Belt and Road Initiative?

Question

Could there have been advantages to extending an invitation to North Korea to observe the Belt and Road Initiative?

https://en.wikipedia.org/wiki/Belt_and_Road_Initiative

Observers

 North Korea[72]

https://www.ndtv.com/world-news/china-invites-north-korea-to-belt-and-road-summit-2025537

China said Friday leaders from 37 nations and North Korean representatives will attend a summit for its Belt and Road Initiative next week as it hit back at criticism of the massive trade infrastructure project.

China invited North Korea to be an observer, but I can't see any good reason to do so. North Korea is a nation under heavy sanctions that doesn't have strong relation with many countries, and it's a pariah state, so North Korea being invited as an observer won't give legitimacy to the project, and I am under serious impression that this move doesn't really have a purpose or yield any significant benefits.

Answer 1

Question:

Could there have been advantages to extending an invitation to North Korea to observe the Belt and Road Initiative?

North Korea is a close ally of China. It's North Korea's closest military and economic ally. Given North Korea shares a border with China and already has infrastructure in place to facilitate the large trade shared between the two nations, North Korea is not dependent, nor necessary as a belt and road participant. It's still polite and smart for China to invite them; as North Korea is rather sensitive about being excluded from such summits, especially by their friends.