One of my group is playing a Vinvocci. He was originally trapped in Victorian London and does have a Shimmer as a Gadget (I think I cost him a couple of Story Points).
This weeks adventure they were up against Silurians. In a bluff attempt he wanted to change his Shimmer to a Silurian, the Time Lord PC made a roll of 24 with Ingenuity + Technology to make the adjustment.
At this point I gave the Player the option; 1. You can store up to six alien race alter-images in the Shimmer or 2. Each time you switch the image you roll 2D6, on a roll of a double 1 it will short out and you will have to acitvely get it fixed or even spend Story Points to replace it.
I figured this will stop it's over-use but wondered if anyone else had used Shimmer's in their game and what restrictions if any they had come up with to keep game balance?
"There's no use being grown up if you can't be childish now and then."