On the bitness: you correctly selected "Format: FITS" which currently gives 16 bit / channel .fit files from my Sony A7S mark i. I presume yours will be the same.

Go ahead and set "Bits per pixel" to 16 as well. This setting syncs with the Format option above. I have noted that when I set the Format to 'raw' the setting will default to 8 bits. This is then causing problems with Ekos truncating the 12-bit data to just 8 bit and the view can show clipped data that in truth is not clipped. Not all is lost though because the saved .arw file still contains the 12-bit data and is nice and small because losslessly compressed. It's just something to consider when estimating your best exposure time and such.

Bye now, J.