QTreeWidget keyPressEvent: Asterisk can be very slow

I have noticed the following performance issue with QTreeWidget:
when asterisk is pressed and at least one child of current item is visible, interface freezes for several seconds (for large tree);
but if no child of current item is visible (item is collapsed), expanding all nodes after pressing asterisk is instantaneous.

Simple workaround for asterisk performance issue in user code:

// class TreeWidget : public QTreeWidget
void TreeWidget::keyPressEvent(QKeyEvent * const event)
{
    if (event->key() == Qt::Key_Asterisk)
        currentItem()->setExpanded(false);
    QTreeView::keyPressEvent(event);
}

I would guess that the following simple workaround is possible in Qt code:

void QTreeView::keyPressEvent(QKeyEvent *event)
{ ...
    case Qt::Key_Asterisk: {
[+]     collapse(current);
        ...
}

EDIT: this issue is only present with

tree->header()->setStretchLastSection(false);