This has one positive side effect: ViewData no longer re-saves an ORDERCLAUSE to registry after it has been read. At the same time the ORDERCLAUSE is read everytime when grid is filled, not only the first time. Those changes were needed to be able to apply an ORDERCLAUSE which was generated and saved by the new dialog.
Left for later: Moving order-columns up and down. Tested that with a TUpDown which seems to ignore clicks sometimes and then doesn't fire OnClick.