Add an optimized append() method to TextEdit

Use-case:
I have a QProcess that emits standard output to TextEdit in qml. As the QProcess runs, it appends messages to a TextEdit. As the TextEdit's text grows in size, performance degrades to the point of freezing the main thread.

Issue:
I suspect that the TextEdit recalculates its size when qml assigns new text to it. This size calculation performance degrades linearly as text length increases (which is expected.) TextEdits have no way to efficiently append/insert text into TextEdit programmatically. See example below:

Rectangle {
    width: 360
    height: 600

    TextEdit {
        id: textId

        anchors.fill: parent

        function addText(newText) {
            text += newText;
            text += "\n";
        }

        //Handle signals from QProcess or something that's emitting lots of text signals
        Connections {
            target: talker
            onTalk: {
                textId.addText(newText);
            }
        }

    }
}

Users can easily append or insert text at the cursor position, without performance issues.

Possible resolution:
Add functions into TextEdit to insert/append text at position in the TextEdit's document. QWidget programmers can easily do this using QPlainTextEdit::appendPlainText().

Attached is a example program showing the issue.