  We constrain the deceleration-acceleration epoch, namely the transition
redshift $z_{tr}$, adopting model-independent techniques that utilize a
calibrated $E_{\rm p}$-$E_{\rm iso}$ correlation for gamma-ray bursts (GRBs).
To do so, in addition to real data points, we employ up to $1000$ simulated
observational Hubble data (OHD) points. We then calibrate the $E_{\rm
p}$-$E_{\rm iso}$ correlation by means of the well-consolidate B\'ezier
polynomial technique, interpolating OHD up to the second order. Once GRB data
have been calibrated, we consider two strategies of cosmographic expansions,
i.e., first we take a direct Hubble rate expansion around $z_{tr}$, and second
the expansion of the deceleration parameter around the same redshift, but with
a different order. Employing type Ia supernovae, baryonic acoustic oscillations
and GRB data sets, from Monte Carlo analyses we infer tight constraints on
$z_{tr}$ and the jerk parameters at $z=z_{tr}$, namely $j_{tr}$. Our results
are extremely compatible with previous outcomes and confirm the $\Lambda$CDM
predictions, being slightly different in terms of the jerk parameter. In this
respect, we conjecture which extensions of the concordance paradigm are
possible and we compare our findings with expectations provided by generic dark
energy models.
