Integrate code from one feature to another

Is there a way to add code from one OT Feature to another?
It’s seems that only aalt can use :

feature xxx;

I’m looking to try a workflow to build Stylistic Sets usings multiple Character Variant features.
For example, I would like to generate the code for my .ss01 by merging code from .cv01
, .cv02 and .cv03

You cannot integrate code from automatically generated features. If the cv## code is manually written, you can wrap the sub … by … rules in a lookup block (lookup XYZ { … } XYZ;) and then invoke that block in other features like so:

lookup XYZ;

where XYZ is a placeholder for a more descriptive lookup name.