I worked for the inventor of this processor. I ran many many processes from 1965 on using the small one. The thing is, with RA4, you run the risk of crossover and cyan fog. The CP5 process was rigged to retard the cyan layer due to the high surface agitation. The rinse after development was there to allow the yellow layer to catch up with the top two. I have never used this for RA4.
I have the original model of a print rocker produced by a person from outside EK who proposed it. It was very difficult to use and to get uniform prints. The guy finally sold the concept to Heath and they sold the print rocker for a few years. It is tucked away in my DR. My boss, the inventor of the drum, gave this to me when the EK trials were done. I guess it belongs in a museum somewhere. I've got lots of these kinds of odds and ends.
PE