In my kit EMs, the skins don't typically sink until about 2 weeks in (when fermentation has reached sub 1.000). Makes sense. The same holds true for my FW kits.
I didn't try an EM with the two kits I have going, but snapped the lid and airlocked the wine at about day 8 or 9, and sloshed the wine over the skin bags 3 times a day to keep them from drying out. At two weeks, I opened them up and punched the skins down before taking a final SG. They didn't come back up again and my SG was about .996. I waited a couple more days and nothing changed, so I moved on to the next step.
I didn't try an EM with the two kits I have going, but snapped the lid and airlocked the wine at about day 8 or 9, and sloshed the wine over the skin bags 3 times a day to keep them from drying out. At two weeks, I opened them up and punched the skins down before taking a final SG. They didn't come back up again and my SG was about .996. I waited a couple more days and nothing changed, so I moved on to the next step.