It would be practical to at least have some form of heat transfer to the case for passive cooling advantage, but this can have the downside of the end user getting burned/uncomfortable and saying, Why does my computer get so hot?

The recent metal-cased RTL-SDR's from rtl-sdr-blog have this "problem". The metal case actually helps the chip run cooler, but it gets hotter to the touch then the early insulating plastic models.