Very interesting is that there are NO mergers of the same mass, which is just in line with Quantum FFF Theory, which states that same mass BHs can not merge because they must separate again after pairing to form Herbig Haro systems with star/ galaxy formation in between. see: https://www.sciencedaily.com/releases/2018/12/181203111617.htm?fbclid=IwAR1pzKDrfUrEEvVvoICqHIk95J8UL07Ii14ee9DhRFq1rDl78rhBqMyb0Fg
and also for explanation:
Black Hole Nuclei as a Bunch of Rigid Transformable Higgs Strings Splitting by Relative Small Companion Mergers or Decreased Vacuum Pressure.
see: http://vixra.org/pdf/1707.0189v2.pdf
The Semi Classical Model of Quantum FFF Theory based on Symmetric Transformable Entangled Rigid Strings.
http://vixra.org/pdf/1711.0443v2.pdf