There are so many subsets of the theory and I have no idea what would interest you and what you already know. Have you seen this paper?
https://www.researchgate.net/publication/220231906_The_Origi...
It leans a bit more on the cybernetic side but gives an overview and has what is possibly equally important as the text itself: some 7 pages of references. I started with openly accessible academic papers instead of books. If you find something interest there, you will surely have the direct reference to proceed further into that direction right at hand. Papers are shorter, you can switch the direction more easily. The price to pay is to miss the bigger picture a couple of times (which a book may convey) until some loose ends come together and create an aha moment.
(given what you said I would stay clear of all reinterpretations/popular science books. I would read something straight from the source, the people in the field, in whatever form it may show up.)
Thanks for that paper! It looks like a good jumping off point. I am primarily interested in the cybernetics side (feedback loops, etc) but applied to social or economic systems, as well as the intersections with Deleuze and Guattari style process philosophy (looking at how every level of the social system, including individuals, is composed of nodes in a network of flows (of desire/memesis, knowledge, material resources, ideas) that the nodes are both somewhat composed by and also transform/switch/break)
The social side is, among others, massively covered by Niklas Luhmann, the Zettelkasten guy. [1] is pure 2nd Order Cybernetics. The entry to it is a bit tough, it uses its own language. The precision presented, however, is brutal and you can’t get larger in scope, as it encompasses society as a whole, corporations, law, communication, all of it.
[1] Theory of Society, Volume 1+2
[2] https://en.wikipedia.org/wiki/Niklas_Luhmann
Oh I didn't realize Niklas Luhmann as the Zettelkasten guy! I use an org mode Zettelkasten (currently migrating to https://iwe.md for reasons) every day for my thoughts and ideas!