Kodak was saying they would redo e6 chemical and control strips in 2019,and of course after they sold chemical and paper businesses to sino,this target will have no hope to happen I think...
You can also make your own control strips. There's actually device (I forget what its called but I have one lying around somewhere) that can automatically expose the strip on any piece of film, but you can also just make one yourself out of a transparent step wedge. Have the strip developed somewhere you trust to have a well-controlled process, and then use that as a reference.
