If you read what I have written about Epson Printheads, then I did mention that the issue if air entering the nozzles is statistically based. Whether it happens each time or not etc is based on a lot of factors. However the printer does try and take care of it the best it can based on estimates by the engineers. If the estimate is wrong, then air gets in and is not flushed out. Now based on what I have seen, in your submission, initially there were a lot more than 3 missing steps. I picked it up right away. The fact that even when you looked and did not pick them up, tells me that text was being printed and there were missing gaps but you never noticed. This is expected. If the printer is used like this everyday for a period, it is not good and a real clog can develop because of this. I fear this is what happened in your situation.
On photos, we would see some minor banding right away on text, a few missing bars can go undetected.
Precision Core printheads are really a newer way of fabricating the printhead and squeezing more nozzles in less space. It is a breakthrough for Epson as previously their printheads were very costly to manufacture. I'm not sure it is a technology for better reliability. It could be, but its main reward is lowered cost per nozzle.
