Thomas 'PointedEars' Lahn writes:

Going proportionally, the secondary black holes are 8 & 14, so I would
guess that would result in 2 solar masses of gravity waves, and 20 solar
masses of new black hole.

Not quite. If you read the paper at PRL (which you can for free again,
thank you LSC and VC), you will realize that naive arithmetics does not work
because mass–energy is only one component of a body’s energy:

In the online story I read, the black hole masses were 14.2 and 7.5 solar
masses and the resulting final black hole was about 20.8 solar masses,
producing 0.9 solar masses of gravitational radiation. But the
uncertainties in all figures was rather large.