Merging and splitting black holes in supernova nebula should be the source of the Flashes and the repeaters!!
Because in nebula the small former starspot -black holes seek the larger BHs to split them and make two equal sized BH as a base for Herbig Haro systems and new star production.
and:
The Magic of Life- and Matter Creating Self Propelled Electric Dark Matter Black Holes
http://vixra.org/pdf/1705.0026v1.pdf
and:
https://www.space.com/42943-fast-radio-burst-repeater-new-discovery.html