How to configure settings for plugins in mu-plugins?

How do you configure plugins that you want to be in mu-plugins so that they're sitewide and users can't change the settings?

For instance, with wpsupercache if you put it in mu-plugins then blog users can't turn off cacheing, but you also can't use the admin panel to configure the plugin.

What is the solution? Do you edit each plugin and hack the code to check if the user is an admin before allowing them to see the settings panel?