[marco]

ISO 50 is not changing the RAW file, it is simply setting a offset. So if you shout manual with ISO 50 there should be no differences to ISO 100. But you move the sampling of the jpeg and preview 1 EV to the highlights. Which is very near to the real limit. If you reduce the contrast in the picture styles you can see some clipping in the jpegs which is not present in the preview. You simply have to test the settings which are working best for you. This is what I do in the RX1R II but I think it will be not that different on the 6300.

 

I use DRO  +5 simply to get a better preview.