That is correct. If you wish to use Client Filtering to filter all the nodes, LoadOnDemand should be set to false. Otherwise the filter will occur for the nodes that are currently loaded and you will have to expand them in order to be able to filter the child nodes.
On the side note, if you wish to get faster responses, I suggest opening a support ticket, so that you can benefit the 24-hour response time of your Support Package.
Let me know if you have any further questions.
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