Used @a4refillpad's excellent Ikea Blinds driver.
Used the default Philips Dimmer Button Controller v2 driver.
Tried controlling the blinds using the Dimmer Button Controller, but that really wasn't designed for blinds, and the app and driver didn't work for constant level changes when holding down a button.
(notes: "unknown device 3" is my hue dimmer, and "switch 36" and "switch 37" are the ikea blinds. You'll also need to change the name of the blinds device in the expressions to make that work.)