[cxS]

Mono doesn't modify the standard, though, because the standard Microsoft sent to ISO leaves a lot of things out

Like what? There's a reason some things were left out because they are old legacy methods from a castaway VB6 for instance.

I only need to debug the program in one environment.

This is not true, because even if you can guarantee that the code will run the same, not all environments are guaranteed to be the same, making a possibility that your code won't work anyways. You still need to test across different environments.