QUOTE (Bigity @ Jul 17 2013, 04:09 AM)

You have to learn key knowledge's, then threads into the items' pattern....wait, never mind.
I've never allowed it, for the same reason you can't 'upgrade' your WR2 to WR3. You can rip them out and replace them, but you can't upgrade the existing item.
Except, you sort of can: You can credit the essence lost against the (now removed) WR2 towards the essence cost of WR3. You cannot do that with the karma spent on a focus. (And since you can buy WR2 second hand, it stands to reason that you can sell your old WR2 to offset the cost a little, like trading in a car.)
So I don't really have an issue with upgrading a focus from a balance point of view. Also, with the new Qi focus tattoos, I like the idea of adding to a tattoo to make it more powerful. Just make sure you have enough Legend Points to....never mind.