How many rags you guys got!?
If I did 20 test prints per job, we'd need like 300 shirts a day... No to mention the time.
We reg it, and send a first gunny pig actual shirt, and if it looks good, we run and adjust. If the red for example ( the most prone to build up and get stronger throughout a run in my opinion ) needs adjustment, we just dial back the pressure / adjust squeegee speed / tone it down. ( Beauty of a challenger IIID is it can all be done from the press operators station )
I think managing customer expectations is important too. "There may be slight variations in a run of 150 shirts as the colours build up and self adjust, If that is an issue order 5000 shirts and they will all be relatively the same on average

" Most people are fine with it. Pierres clients obviously notice and care about it, I am lucky to have mine who don't!