  We use the recent statistics of dual active galactic nuclei (AGN) in the
$James \ Webb \ Space \ Telescope$ (JWST) data at $z \sim 3.4$ to address two
aspects of the feedback and evolution scenarios of supermassive black hole
binaries (SMBHB). We find that the JWST data provide evidence for the members
of a binary black hole being 'lit' at the same time, rather than independently
-- a scenario which is consistent with gas-rich mergers being responsible for
concurrent AGN activity. This conclusion is supported by the recent NANOGrav
Pulsar Timing Array (PTA) measurements, whose upper limits on the stochastic
gravitational wave strain amplitude lie below those expected from extrapolating
the dual AGN fraction. The results indicate either a 'stalling' of the binaries
at the separations probed by NANOGrav, or rapid gas-driven inspirals.
