BK's use of Markov's blankets in explaining alters seems contradictory to the idea of "direct experience". A Markov blanket, as I understand it, is system contained by a boundary with an internal representation of the external world. Across the boundary inputs come from sensory perceptions and outputs are generated in actuators that can affect the external world. Our experience isn't directly of the external world but our internal representation of it. This is how I view consciousness or at least "alter" consciousness.
I can agree with this: "all we can know is the experience of the phenomenal representation of the noumenal thing". This would correspond to the internal representation, but that representation is already an abstraction from what exists in the external world. Perhaps, this experience is most direct experience we can have but it is far and away anything but direct. It might be the best we can do it seems mistaking the representation for the real world would be like mistaking the painting of the pipe or the real pipe.

https://en.wikipedia.org/wiki/The_Treachery_of_Images
The problem is there isn't any escaping the dilemma.