Looking at the User Manual for 3.2.6, it appears to refer only to 3.1
So, what are the ‘right’ settings for Low Level Playback Options?
I think Exclusive Access and Integer Mode are obvious from reading the manual, but not whether to check “Use large CoreAudio I/O buffer”?
Since you don’t mention Direct Mode… which is the best low level playback you are on Sierra or high Sierra.
I never found that it change something when i didn’t have Direct Mode loaded.
Doesn’t cost much to check it for a couple of days if it change something for you… like your Clicks when DSD256 
Yes, High Sierra.
Tried all combinations and cannot stop the dropouts on DSD256