Hi Kim,
Greetings from Syncfusion.
At present we do not have support for “Zoom the PDF in the page level” in SfPdfViewerControl in UWP. We do not have any immediate plans to implement this feature. At the planning stage for every release cycle, we review all open features. We will let you know when this feature is implemented. We usually have an interval of at least three months between releases. The feature implementation would also greatly depend on the factors such as product design, code compatibility and complexity. We will update once the feature is available in SfPdfViewerControl.
Regards,
Sathish