Hi Tam,
We have analyzed the feasibility of this request, But none of the viewers like Google Chrome, Firefox, Edge and Adobe Acrobat have this support. This is because of complexity in rendering the selected area into the view. This will affect the current architecture on the virtualization. So, it is not possible to provide support for zooming a particular area in the PDF Viewer. Please revert to us, if you need further assistance.
Regards,
Dhivya.