Do i have to update to lighroom 5.4?
Yes, if you want to open D4S Raw files in Lightroom since Raw support was first added in 5.4.
Camera Raw plug-in | Supported cameras
Or you can continue using the DNG converter.
Obviously the latest camera raw does not attach itself to lightroom...
Camera Raw is a Photoshop plug-in. Lightroom does not use Camera Raw as a plugin. The Camera Raw engine is built in to Lightroom's code.