I would have to reflect on that more and maybe reread those chapters. Tbh, the "metaphysical grammar" part went over my head.

A quick glance back at those sections did raise a question tho. I think there could be a formulation of GSC/EP that incorporates an element of karma. I read a book by Thich Nath Hanh where he suggests that if one practices mindfulness exactly as he does, then that's as close together as him and they can ever be. In that moment, they are basically one by virtue of the fact that their states of consciousness have aligned. This got me to thinking that one could add karma into the thought experiment. Why should the existential passage be from me when I die into the next body that has consciousness? Could we not also envision a sort of existential passage where the continuity is between two minds with a similar state of consciousness. This could be seen as analogous to karma. My actions cause me, in this life, to be reborn either into a "hellish world" or a "heavenly world" in my own mind: from moment-to-moment, I am reborn this way. When I die, could not we imagine that the passage goes from my body and into the body of the next person with that same "heavenly" or "hellish" state of consciousness that I had in my final moment? that insofar as actions determine our state of mind, actions (karma) could thereby affect our next destination?

I think this would be compatible with the Buddhist teaching. This is one way of looking at the "provisional" teachings of the Buddha about rebirth and karma. Ultimately, there is no individual self and the prajnaparamita sutras explicitly teach that rebirth/samsara is illusory and is a "provisional" teaching. Ultimately, there is no self transmigrating and, if we think about it long enough, we'll end up wondering if the existential passage ought not to be conceived as going from the body of the one that died into the bodies of ALL conscious creatures still living and that ever will live.