The Small Format Printer Maintenance Video does not really relate to either of these models because you can not actually inject any cleaning solution into the print head. THe R3000 uses a head which if not a 3880 head looks exactly like one - side by side, top to bottom including the dampers. There are long ink lines in between the ink tanks of an R3000 and a Pro 3880's print head. So to clean it is not as easy as cleaning an R2880. With the R2880 for example, when you remove the cartridges, the ink stems are just above the print head.
The principles are the same but you may have to go about it quite differently. PiezoFlush is not recommended to be injected into the ports of these two printer models because the dampers on these printers are very fragile and you can easily blow out the seal resulting in a leak of air and a very long and convoluted repair which you may regret. Our users have injected into the R3000 and have reported here no problems. At the same time, we have customers here on the forum who have caused themselves headaches not following our advise. So proceed with caution.
If you install a set of cartridges with PiezoFlush into the R3000 you can then run the INITIAL FILL of the Epson Service Utility. It takes about 8 minutes to run and is the equivalent of 70 head cleanings - which is how many it takes to thoroughly flush an R3000 ink lines, dampers, and print head. We do not recommend running that many head cleanings or you will kill the printer. For the 3880 you have the luxury of using the POWER CLEAN function and it takes three of those to thoroughly flush the ink lines, dampers, and print head. You can then move the print head out into position to clean the underneath as in the video.
Let me know if you have additional questions.