Automatically clearing theme registry for specified role.

I can imagine that if you're creating or changing a theme it can be annoying to constantly have to clear the theme registry.

I think it's a good idea to change the theme registry so that it clears at each page view for specified roles only (say themer or admin).

Checkboxes on the admin/build/themes/settings page could be filled with the defined roles. Every checked role would then always have the most updated theme settings.

An argument against this would be that it's slower, and that people might forget to turn it off after working on the theme and that the site would continue to be slow for that certain role.