ADS1299EEGFE-PDK: Anti-aliasing filter of ADS1299 PDK

Hi,

I came across this thread regarding the anti-aliasing filter design for delta-sigma ADCs. It suggests to choose the differential filter’s 3-dB cutoff frequency, fC-DIFF, such that it is 10x to 100x lower compared to fMOD. 
In the PDK, clearly the board is equipped with anti aliasing filters of 6.8kHz.  

fMOD  of ADS1299 = fCLK/2 = 2.048MHz/2 = 1.024MHz

Thus the range for the anti-aliasing filter is given by:

     10.24kHz <  fLP <102.4kHz

Here are my questions : 

1. Why the value for low-pass filter was chosen to be lower than the suggested minimum value in the guideline?
2.  Currently I am ahering below guidelines when designing the anti-aliasing filter, please let me know if I am missing something ?  

   1. fLP  >> sampling rate configuration of ADS1299 

   2. fLP  shall be at least 10 times the bandwidth of interest 
   3. fLP  shall be higher than the 3-dB frequency of the ADS1299 configuration(from Table 1-4) 

We are interested in detecting R-peaks of fetal QRSs reliably by choosing these values. 

Thanks,