Very interesting research and speculation there.
I agree with a large portion, though wonder if Sleeper-Talocan relations were as benevolent and being contemporaries, or whether the sleepers took Talocan technology they found useful after the Talocan made the mistake of making their bed near Sleeper facilities.
The idea of there being a massive centralised hub (Dyson spheres) for power generation would make sense, the energy demands of capsuleers and the big four are already astronomical and even if there are more advanced power generation methods than solar power (antimatter reactors and so on), kick starting fuel extraction and refining with 'free' energy is a sound economic decision. The Sleepers have the technology, time and need for a Dyson sphere, especially with the energy requirements outlined in the OP link. This may address their energy costs much more neatly and in a central, easily maintained manner compared to the distributed, ad hoc energy generation of the big four and capsuleer empires. Note that the k-space energy need may be orders of magnitude lower than the Sleeper's power needs, and is still massive by any imagined standard.
Add to the power siphoning sphere an FTL transport method for transmitting energy and material across the Sleeper domain and we have a recipe for some extreme industrial accidents if it is tampered with or neglected. A cache of iso-5 detonating is going to ruin your day with solar fire. An iso-5 breach casting wormhole generators into the corona or mantle of the host star while active, is going to be catastrophic, especially when those conduits outside the star may still be jetting a volatile mix of dying sun and iso-5 into the now shattered wormholes.
Caroline's star may well have been swiss-cheesed by wormholes and ravaged by iso-5 leaks, possibly due to break down of tech, possibly due to Sansha tampering (having stolen the tech) pushing the system too far. The end result is there for all of us to see.
I like this kind of speculative work, and the author nails the spirit of it nicely.