Google Model Viewer – is there a way to add custom cursors?

Question

I'd like to customize the Google Model Viewer cursors, but haven't been able to do so using the CSS cursor property. I'm using the release version. I've tried both custom images and generated CSS cursors, both of which work fine on the rest of my site, but the viewer always defaults to the generated cursors 'grab' and 'grabbing'. Is there a way to replace these using the release version?