Question about Epic Potential Scroll

When I used one on my unpotentialed bow, it came with a hidden pot after.

You can use it with un-potentialed items now?

......Duh? Hidden potential is always the middle step.

I wouldn't put it past Nexon to just give your item the [epic] title, only for you to need to re-cube it for new stats

EDIT:
This seems to be confusing some people (probably due to my wording)
My main worry was if I used an epic potential scroll and it worked, it would keep my potential stats the same but only change the title from rare-->epic.
I understand now that it gives you a hidden potential epic and you have to reveal.

Does anybody know if your # of lines ever changes?