Hi Russ,
Thank you for using Syncfusion Products.
At present we do not support clicking on the hyperlink navigates to the respective pages in the PDF document. We will consider your requirement while implementing the hyprlink annotation feature in SfPdfViewer in Xamarin.Forms. We will implement this feature in any of our upcoming releases and usually we have three months of interval between the each release. The implementation of this feature would greatly depends on its feasibility and code complexity.
Please let us know if you need any other assistance.
Regards,
Sathish