Well--I guess I misread your post then, I thought you were asking about running color in your shop...I run E6 where I work, and we deal with both Kodak and Fuji tech support--yes, they do want to know about your plots. It will be one of the first things they ask you, and some of your customers might be interested in them as well. There's just so far you can get with E6, and I would assume C41/RA4 -but my work experience in labs has been that you standardize with process control--via control strips. I run a b&w deeptank line, an E6 machine and a roller transport b&w processor as part of my job now.

FWIW--there are a couple of ways to offer these services as you say--(but still, when I read what you're saying about the RA4 and such, it just makes me nuts almost--from a lab standpoint.) But for b&w, you can either set up a custom line, where you hand-tailor your process to each film. Or, you set up a line where you run it all the same, or in batch times where you break the film out for a couple of different times. You can use Kodak control strips for the b&w. The strip is based off TMY stock. They have a manual called "Monitoring and Troubleshooting Black and White Film Processes"--Z133E. The E6 manual is Z119, and is a big binder-with the control charts etc. B&W is pretty easy compared to E6--I quit running control strips for b&w years ago, but run them for E6. You'll need the right densitometers of course for each process, and the control strips will need to be kept within date, and in a freezer just prior to your run. You'll need to either run them first thing, or at set periods through the day--or as needed. It's very important that you do things the same every time. If you run the strips by themselves--always run them alone. If you do it with a run of film--always have them in the same location in the tank, rack or tube. There is no "winging it" to this sort of processing--you need to be like a robot....it's a job, it's not exactly fun, but it's not rocket science either...it can be fun, but it needs to be repeatable to the point of where you can do it with your eyes closed on autopilot... all the above for chem mixing & maintenance as well.These are the standards most pros want their film to be processed against--and believe it or not--Kodak and Fuji do care about your control strips. They have no way of helping you otherwise.

Good luck with your business though. Hope this helps....

p.s.-- if you're interested---Aristo makes an additive color head for printing color. it's a coldlight with red, green and blue tubes.