PTInk with custom appearance not displaying in built in iOS viewer

I'm creating a PTInk annotation in a PDF document, the applying a custom appearance using the element builder path methods (I. E. Move to, curve to). With PDFNet this renders as expected, however if I export the PDF to mail.app on the iPad, I am unable to see the custom appearance created by the element builder. How do I create an appearance stream using the element builder path methods that will display in the standard iOS viewer used by mail.app?

If mail.app is like OSX Preview, then it actually ignores any appearance stream, and always generates its own. OSX Preview is the only PDF reader we have observed doing this.

If the appearance that you set is appearing correctly in other PDF readers, then the issue is with mail.app.