EQUAL SIZED BLACK HOLES DO NOT MERGE, BUT FORM HERBIG HARO SYSTEMS.

New Black Hole Physics of Quantum FFF Theory:
Equal sized black holes with <15% ratio differences do not merge 

(see LIGO/VIRGO)
As example: all dual Herbig Haro hotspots (bowshocks) see:https://www.ligo.org/science/Publication-O3aCatalog/ 

"Mass ratio and total mass estimates for all O3a events. Contours represent 90% credible intervals. Six unique events are highlighted"

Q-FFF Theory says: Black holes do repel Fermions (mass) by their rotating propeller forms pushe away by the spacetime concentration at the BH horizon, which is the origin of Herbig Haro forming a pushing plasma bar between the two BHs.

See also: Herbig Haro Astrophysics Based on Dual Rigid Strings. https://vixra.org/pdf/2007.0158v1.pdf

See the plasma bar already between even different black holes below, before the splitting process..

Splitting example of splitting black holes forming two equal sized BHs and a different third one.