  The spectral evolution of transient X-ray binaries can be reproduced by an
interplay between two flows separated at a radius $R_J$: a standard accretion
disk (SAD) in the outer parts and a jet-emitting disk (JED) in the inner parts.
In the previous papers of this series, we recover the spectral evolution in
both X-rays and radio for four outbursts of GX339-4 by playing independently
with the two parameters: $R_J$ and the accretion rate $\dot{M}_{in}$. In this
paper, we compare the time evolution of $R_J$ and $\dot{M}_{in}$ for the four
outbursts. We show that despite the undeniable differences between the time
evolution of each outburst, a unique pattern in the $\dot{M}_{in}-R_J$ plane
seems to be followed by all cycles within the JED-SAD model. We call this
pattern a fingerprint, and show that even the 'failed' outburst considered
follows it. We also compute the radiative efficiency in X-rays during the
cycles and consider its impact on the radio--X-ray correlation. Within the
JED-SAD paradigm, we find that the accretion flow is always radiatively
efficient in the hard states, with between $15\%$ and $40\%$ of the accretion
power being radiated away at any given time. Moreover, we show that the
radiative efficiency evolves with the accretion rate because of key changes in
the JED thermal structure. These changes give birth to two different regimes
with different radiative efficiencies: the thick disk and the slim disk. While
the existence of these two regimes is intrinsically linked to the JED-SAD
model, we show direct observational evidence of the presence of two different
regimes using the evolution of the X-ray power-law spectral index, a
model-independent estimate. We then argue that these two regimes could be the
origin of the gap in X-ray luminosity in the hard state, the wiggles and
different slopes seen in the radio--X-ray correlation, and even the existence
of outliers.
