Opentype features in KLWP


I'm currently designing a font I'd like to use in KLWP using opentype features to alter character shapes based on context.

One example is tabular figures (all numbers occupying the same width, so that the time doesn't jump around every second/minute). In for example notification text, or temperature/forecast text, this doesn't apply, and I wouldn't want the 1 to take up the same space as the 4.

Is there any way in KLWP to select which opentype features to use?