QBlitFramebuffer's setSource and setDestination does not automatically set a parent for the provided QRenderTargets when there is no parent yet. This is unlike other framegraph nodes. Compare with QRenderTargetSelector::setTarget for instance.
This becomes particularly relevant in the use cases shown in
QTBUG-65080, where there are QRenderTargets that are used only in combination with QBlitFramebuffer and are never associated with a QRenderTargetSelector.