In short: it would be very hard. There's a complicated data pipeline leading to the UI. It depends on how much value you would get out of such a tool. It's not a priority for us to make this generic beyond the scope of WMF projects, but it's not an inflexible piece of code.

In theory, you should be able, with a few months of effort:

• fork wikistats
• customize the wmf-specific configuration
• stand up an API that's compatible with the way wikistats calls the AQS API
• test and get it deployed

If this is important to you and you go down this path, try to keep the changes as isolated as possible from the rest of the codebase, as we'll eventually release improvements and you may want to update.