At least report to Epson the fact that your vivid light magenta is regularely giving you issues, even if you cal clear it. Ideally, demand that they fix it. Have them note innyour file that the issue was there before the end of the warranty.
The cyan of my 7900 constantly had missing nozzles, but i could alwYs bring them back fairly easely, during the first year after purchase. Only cyan, no other colors. 2 months after warranty, half the cyan went out and i could not bring them back. Called epson. They said sorrry, and since i had not called them before, they did not want to accept that the symptoms were there before. My printer is now scrap. Cost to much to fix it. In fact i don't even believe its a clogging issue. I think its an electric issue in the head and bad qualify control.