You can use Mendix client apis in widgets
https://apidocs.rnd.mendix.com/9/client/index.html
The platform SDK is used for build-time changes to the app model, while the pluggable widgets API is used in creating widgets leveraged at run-time. So really they don’t belong together.
Can you explain what project parameters or information you need in the widget? Maybe we can help you find another way.