True body diode reverse recovery should only be about the
current during the below-ground interval. This imparts the
diode forward charge that has to be taken out by the high
side (-if-- the remaining low-side-switch on time (Vdb=0)
has not been enough to do so).
You ought to be able to bench-measure body diode recovery
time in the classical manner, against on-current and temp,
change the "-1V" bias to 0.0 and see what the 'scope tells.
I'd be inclined to worry more about frequency & duty as the
determiner of "off time available to bleed body charge" and
current as determiner of that charge, than VIN (other than
as VIN requirement moves you from device P/N to P/N,
changing all the details).
While a hard-applied high state surely will speed the recovery
(V=I*R discharge) I think you do not want to have a design that
hits hard into a still-charged low side body diode.