Given the following example string: "h\U0001F600\U0001F5FFy" (JIRA is incapable of storing the actual string)...

To start, let us note that this text is rendered perfectly fine in traditional Qt Widgets applications. However, in Qml, the characters U+1F600 and U+1F5FF are rendered as blank (with Text.QtRendering) or as solid-color silhouettes (with Text.NativeRendering). The problem is not necessarily specific to these two characters but assumed to be specific to the characters provided by the "Apple Color Emoji" font. Explicitly specifying this font in Qml has no effect.

Font substitution also seems to be a problem, as U+1F701, provided by the "Apple Symbols" font is displayed as the Unicode replacement character unless the "Apple Symbols" font is explicitly specified.

Example app and screenshot are attached.