It's quite possible. Not everyone is able to channel aether directly, after all, and no one really knows until they actually use it.

But as for a "focus"... In my world, we did have something like that—the crystals. They were the only items that could absorb and release aether. However, they had a short, limited use, which is why Bearers were used the way they are.

And now in this world, I'm not sure how it would work. Frankly, I'm not even sure if there is "aether" in this world as we know it. Not even the tattoos draw upon our aether, we can actually mix the magic from this world with our own.