I have test the cell type “ch” with a header colomn “#master_checkbox” but i using the smartrendering mode with the loadXMLString.
the master checkbox works whith the lines not hiding only !have you an update wich change the value in all the xml data?
This is known limitation. The #master_checkbox works only with rendered rows, so it not suitable for paging or smart rendering mode.
We plan to extend functionality in future, but so far there is no any useful update.