It is possible to bend LIFX Z strips, up to 90º, when done properly.
Here are a few examples, of what to do, and what not to do.
In the example below, the strip has been bent in a way that damages the strip.
Here's the correct way to bend a strip up to 90º.
For making corners, this is a great way to get the corner for behind a TV, or something else, without damaging the strip.