The approach seems viable in this case. You can check if it is working correctly and apply the data-role: "none" attribute to the necessary elements. The grid does not have only input elements that are picked up by the jQuery mobile styling but also <a> <table> etc. You may need to add those as well to the keepNative option to see it improve the result.
Another thing is try to manually iterate over the inner elements and add the data-role="none" attribute if the other approach does not work correctly.
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