All around keyboard legend Matt3o designed some MX Topre sliders and put them on shapeways, a 3D printing company, a little while ago. I decided to get a few to test out just for fun.
All in all, the sliders worked well. I should mention that they do not have the small “hook” at the top of the slider to hold them in place, so when you install them you will need to hold them from the back as you press the keycaps on. I ordered just enough to put them on a few of my modifier keys, and was fairly pleased with the results. I did lube them and put ironed EK landing pads on them, which is a previous modification I have already done to the entire keyboard.
Now, I wouldn’t go recommending you buy enough of these to cover your keyboard, they are still in the Beta stages, and it would also be extremely expensive. If you want to buy just a few for modifiers, or perhaps an ESC key, these absolutely work.