The idea of the virtualization is to render the rows on demand. Rendering all rows will slow down the Grid or even crash the application if there are too many rows.
If you use the approach demonstrated in the "how to" example which I provided you will have the IDs of the selected records (the `selectOrders` array). It is not possible to get all the <tr> elements, it is possible to store the data records or their IDs.
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