  Thru-hole epitaxy has recently been reported to be able to grow readily
detachable domains crystallographically aligned with the underlying substrate
over 2D mask material transferred onto a substrate. [Jang \textit{et al.},
\textit{Adv. Mater. Interfaces}, \textbf{2023} \textit{10}, 4 2201406] While
the experimental demonstration of thru-hole epitaxy of GaN over multiple stacks
of $h$-BN was evident, the detailed mechanism of how small holes in each stack
of $h$-BN survived as thru-holes during multiple stacking of $h$-BN was not
intuitively clear. Here, we use Monte Carlo simulations to investigate the
conditions under which holes in each stack of 2D mask layers can survive as
thru-holes during multiple stacking. If holes are highly anisotropic in shape
by connecting smaller holes in a particular direction, thru-holes can be
maintained with a high survival rate per stack, establishing more epitaxial
connectedness. Our work verifies and supports that thru-hole epitaxy is
attributed to the epitaxial connectedness established by thru-holes surviving
even through multiple stacks.
