Per Table 25 in datasheet, in high-res mode using sinc5 filter w/ decimation by 64, -3dB point is listed as 6833.54Hz. I calculate roughly 7206Hz per filter description in datasheet, which agrees w/ provided filter model spreadsheet. Is there a typo or could I be missing something?

I calculated by multiplying response of sinc1 @ 128kHz w/ a sinc4 @ 32kHz. I now see the figure/equation you refer to, however, this is just a linear approximation. Is there a more exact way to get the response so that I can employ a compensating FIR filter to flatten response out a bit further? -Dan