No, you are wrong. since fading checks for time runes only at upkeep and if a time rune is moved. A mirror illusion can copy something only: via midband, hence the unit will never see an upkeep(trash it Eot); and maxband, in this case the copying mirror would die next upkeep.
Also, a question, @sharpobject IIRC not long ago was said that if the opponent removes the last TR from my fading unit, it would not fade and stay on the field forever. if this is still true, then the maxb scenario would make another eternal unit (no fading) . Has that been changed? ty