Stampin' Up has finally done it. They've developed their own version of the Misti and I have to say that I'm pretty impressed. It has hinged flaps that allow you to keep 4 stamps in play, not just one.
It's being released at the start in a pre-order, staggered launch. It should be in full release in the 2018-19 catalog.
There's a video out there that demos the tool in use. Have a look! If you're interested and have questions, please let me know.