Reviving this topic as my shop just received some of the "E" toners. My supplier hasn't been able to get ahold of Magenta in particular. Konica has a firmware update and a service bulletin issued for these toners. Firmware was updated on our C3080 yesterday. From what I can tell, it enables additional toner density adjustment access. You can turn on an option to show the toner density fine adjustment on the user side, and in the service side it enables the ability to take density adjustments further than what is normally available, and run the press without toner installed so you can run the developer hopper out of toner.
What my tech and I were kicking around though, is that if we need a developer swap, the new developer is going to come with the original toner in the bag. Nobody has heard about "H" or "E" toner developer powders. It's not stated, but I would imagine if we were already running the "E" toner, they would expect us to remove the toner bottle and run the new developer out of toner as well. The bulletin calls for a service tech to run a duplex test pattern for 10-15 minutes until the toner hopper is empty, install the new toner, then run it for another 2,000-3,000 sheets depending on the model. This would need to be done for each color that's replaced with the new toner. I'm not expecting a credit for the clicks or a check for the paper.
Unfortunately, I'm going to have to tap into those "E" toners sooner rather than later. Hopefully we don't see a major change in density, but I'm expecting a pain in the neck day working through it, and will need to re-profile the press.