  We revisit the suggestion that dual jets can be produced during the inspiral
and merger of supermassive black holes when these are immersed in a force-free
plasma threaded by a uniform magnetic field. By performing independent
calculations and by computing the electromagnetic emission in a way which is
consistent with estimates using the Poynting flux, we show that a dual-jet
structure is present but energetically subdominant with respect to a
non-collimated and predominantly quadrupolar emission, which is similar to the
one computed when the binary is in electrovacuum. While our findings set
serious restrictions on the detectability of dual jets from coalescing
binaries, they also increase the chances of detecting an EM counterpart from
these systems.
