I see this will be good new function to download component without default_grid.php files.

For example, I made component and when I start HTML/CSS redesign, I see I forgot to include some parameter or I put wrong name in field atc.

I need to rewrite those files every time I regenerate component.

We all face the same problem but there is no easy solution.
For my part, i use a mix of
- Dropbox (for revisions),
- a css import,
- Template overrides,
- Beyond Compare to get all the modified bits of code back each time i download the component because i insert a commented line to each modified part.