  We calculate $K\to\pi\pi$ matrix elements using periodic boundary conditions
as an independent calculation from our previous study with G-parity boundary
conditions. We present our preliminary results for $K\to\pi\pi$ three-point
functions and matrix elements on a $24^3, a^{-1} = 1$~GeV, $2+1$-flavor
M\"obius DWF ensemble at physical pion and kaon masses generated by the RBC and
UKQCD collaborations and discuss the prospect for high-precision computation of
$\varepsilon'$ with periodic boundary conditions.
