Thanks for this - a great way to provoke some progress (no pun intended).

I would suggest: move the rows dealing with MPI_PREADY and MPI_PARRIVED between MPI_START and MPI_WAIT, i.e. in the approximate calling order.

Also, I would add “ic” for the new MPI_PREADY, MPI_PARRIVED, etc procedures - because the operation is definitely incomplete at the point in time they are called, during the time interval of their entire execution, and at the point in time they return - there is no possibility they could be completing or freeing procedures.

What are the other footnotes: 7, 9, and 14? (I could look them up but I’d have to choose the same draft version as you because the numbering changed recently.)