Since version 2.7.0, AbleSet allows you to add a measure track to your timeline to define the measures in your songs:
The measure track needs to be called "Measures" and can contain one MIDI clip per measure for your songs. The title of each clip represents the measure that AbleSet will display. This is usually a number, but you can give these clips any name you like.
Creating these clips for all measures in your songs is tedious, so you can use this tool to create measure clips for a number of measures in any time signature:
If AbleSet doesn't detect any measure clip at a given time, it falls back to Live's internal measure.