Sandboxed Solutions are not a very practical way of testing solutions in production. It opens up a world of bad things to happen. That being said, there are still some good things that can come from them.
The blocking solution provided in Central Administration is a complete joke, it won't help you for governing sandboxed solution deployment AT ALL. However, I have built a tool that will solve many of the deployment issues with Sandboxed Solutions. I call it the Generic Solution Validator. It is scoped to a Site Collection level and allows you to ALLOW or BLOCK solutions based on various properties. Properties much more valuable than the SCA provides.
I have posted the Generic Solution Validator to codeplex.