  Transitions among different mechanisms of two-proton decay are studied in
general. The introduced improved direct-decay model generalizes the
semi-analytical models used before and provides flawless phenomenological
description of three-body correlations in $2p$ decays. This is demonstrated by
examples of the low-lying $^{16}$Ne state decays. Different forms of transition
dynamic are shown to be highly probable beyond the proton dripline for the
$s$-$d$ shell nuclei. It is demonstrated that transition dynamic of $2p$
emitters can provide means for extraction of a width of the ground-state
resonance of a core+$p$ subsystem of the core+$2p$ system. Practical
applicability of the method is demonstrated by properties of the $^{14}$F
ground state derived from the $^{15}\mbox{Ne}\rightarrow
^{\,13\!\!}\mbox{O}+2p$ decay data and of the $^{29}$Cl ground state derived
from the $^{30}\mbox{Ar}\rightarrow ^{\,28\!\!}\mbox{S}+2p$ decay data.
