Thanks Bear.  Despite the significant uncertainty from the variables you noted, I think that I can conclude that the dose used in BETonMACE was nowhere near being too high, or causing less BD-selectivity.  In live cells they found only a reduction in BD-selectivity beyond 15 uM, where as in humans apabetalone was registering only at 1 uM (in plasma) per 100mg.   So my take is that you could likely take a much higher dose than that of BETonMACE's without losing significant BD-selectivity, which is critical according to this study.  
That's all I was after.  I am officially relieved of my concern.  Thanks again!