I want to have the Link Metrics With First Master custom parameter to change in a way that you can choose any master.
When you are making a multi-layered typeface and you want to add inline version, you may want to assign different colours in order to see the design with the base layer. However, as my workaround, I need to add transparency to the base because it’s on top of inline. It gets less manageable as you add more layers like shadow, outline, etc.
Alternate solution to this would be to reorder display order of masters, but that sounds more complicated.