So I had a spare set of OEM pulleys to install but before I did so I broke my own rule of changing ONLY one thing at a time.

Since I had to partially disassemble the RD to change the pulleys I decided to pull it the rest of the way apart for a thorough cleaning and de-greasing followed by re-greasing and assembly. Things went predictably until I tried to replace the heavily spring loaded "B" screw flange. The YouTube trick that worked was to clamp a 5mm allen key in the vice to hold the RD while using pliers to rotate the flange in the correct position and holding it to insert the axle clip.

On re-installation I noticed some play in both the mounting axle and the jockey wheel axle. Since both of these are tightly sprung I don't know what effect this might have on shifting performance.

Overall the shifting has improved. I won't know for certain how much until I ride it tomorrow.

I also notice that the new ceramic bushing came with ZERO lubrication from Shimano so I added a little bit of grease. I know that ceramic is hard but I would think that some sort of lubrication would still be necessary.