fact, in the practical QCDF application to the $B$ ${\to}$ $PP$, $PV$ decays (where $P$ and $V$ denote the light pseudoscalar and vector $SU(3)$ meson nonet, respectively), the non-universal values of annihilation phase $\phi_A$ with respect to PP and PV final states are favored (scenario S4) [@Beneke2]; the process-dependent values of $\rho_A$ and $\phi_A$ are given based on an educated guess [@Cheng2; @Cheng1] or the comparison with the updated measurements [@chang1]; the flavour-dependent values of $\rho_A$ and $\phi_A$ are suggested recently in the nonfactorizable annihilation contributions [@zhu2]. In principle the value of $\rho_A$ and $\phi_A$ should differ from each other for different topologies with different flavours, but we hope that the QCDF approach can accommodate and predict much more hadronic $B$ decays with less input parameters. So much attention in phenomenological analysis on the weak annihilation $B$ decays is devoted to what the appropriate values of the parameters $\rho_A$ and $\phi_A$ should be. This is the second issue. In principle, a large value of $\rho_A$ is unexpected by the power counting rules and the self-consistency validation within the QCDF framework. The original proposal is that $\rho_A$ ${\leq}$ $1$ and an arbitrary strong interaction phase $\phi_A$ are universal for all decay 