I am thinking from the perspective of a user of a product like this. I personally do both development and design work.
Your example does not convince me that it would save time ('probably' isn't enough) or be generally useful enough that a designer could be convinced to drop Sketch for it.
As a designer, I want to use Sketch.
As a developer, I want a Sketch design over generated code.
For sure, it is a neat experiment to create something like this, but time and time again, people always resort back to tools like Sketch. I think this developer would be better off spending their time building out a super epic component widget library than trying to build a visual designer.
Your example does not convince me that it would save time ('probably' isn't enough) or be generally useful enough that a designer could be convinced to drop Sketch for it.
As a designer, I want to use Sketch.
As a developer, I want a Sketch design over generated code.
For sure, it is a neat experiment to create something like this, but time and time again, people always resort back to tools like Sketch. I think this developer would be better off spending their time building out a super epic component widget library than trying to build a visual designer.