Thanks again for your quick response, but sorry No!
Think you are thinking of the 64s, anything other than that only has capability to patch the SD card to the Main L+R, Flex mixes or Sub Groups.
All of which are no use as the main mix will have a mix, so BT not separate, and the others are not selectable to record separately.
Sorry if I didn't explain but I have the SL16
Hence the feature request, just to add the Tape input to the record select option for the SD Card!