Nice job.
I didn't feel anything different in the shave post red paste. I'll use the red paste, then black with stropping. If it doesn't enhance the shave, then I'll revisit the ILR finishing stone.
I didn't realize (or I forgot) that you had the ILR. A number of variables at play, but in any case, I would suggest upping the ante a bit with the red paste to see how it affects things, before moving to the black paste. If that fails for you, then I would suggest returning to the Norton 4000/8000 followed by the ILR. For me, red paste after, say, a coticule really makes a difference.
By the way, how are you gripping the shank when stropping? And what sort of gesture do make during the flip?
If you would be inclined to give this a try, start with a practice strop until you have it down.