Maybe I am missing something, but when I calculate the change in either value or NAV of most of the bond funds listed in Charles Bolin's Seeking Alpha article I get far higher drops then the MFO statistics show.
Example VCOBX, MFO lists a DD over last year or during Covid crash of minus 0.8, but the NAV dropped from $21.48 (3/6/2020) to $20.20 ( 3/19), a drop of 6%
There were no dividends paid during this time, and even adding back in a proportion of the dividend of $0.04430 paid 3/31, you still get a drop of 5.8%.
Even the drop on a monthly basis for March is 0.8%.
Morningstar listed the Maximum Drawdown over all time periods as 2.7% from 2017 to 2018.
The definition of Maximal Drawdown MFO uses is " The percentage of greatest reduction in fund value below its previous maximum over period evaluated".