We do not recommend the double underscore trick anymore. Rather, use an incremental metric key in conjunction with automatic alignment. This has been introduced in version 2.3: https://glyphsapp.com/blog/new-features-in-glyphs-2-3
Hey @mekkablue. The ideia looks nice, but there is something that is not working for me. Why I can’t have different values on the the different masters? the value I want to add is not the same in the light and bold master.