You want to dither once and only once. If your goal is to capture 24-bit, keep ANSR OFF. Turning ANSR ON will output 16-bits, in which case you'll have nothing to which you can apply UV22HR (unless you want to dither below 16-bit). So, <1> ANSR OFF, then <2> dither in post with UV22HR (but only after applying any and all edits). FWIW, I recommend checking out some other dither algo's, too. See the
dither comparison thread.
Edit to add: Based on your sig, looks like you're using a DAP1 or JB3 for recorder. In which case, you're only capturing 16-bit, so turn ANSR ON, you don't want to truncate.