SDK Version 3.13 for iOS and macOS is released. This offers much better ability to handle errors in the XML file, if possible showing a valid score even where there are multiple errors, and also allowing visibility of the errors through the warnings API (SSScore.getXMLWarnings).
This release also includes the possibility of saving unique IDs (licence needed) on notes and directions using the new MusicXML 3.1 format. This allows your app to save item handles and reuse them when reloading the same XML file, so overlaid annotations can be placed on the same notes. Please contact us through the contact page if this is of interest