  Simulations of galaxy formation are mostly unable to resolve the
energy-conserving phase of individual supernova events, having to resort to
subgrid models to distribute the energy and momentum resulting from stellar
feedback. However, the properties of these simulated galaxies, including the
morphology, stellar mass formed and the burstiness of the star formation
history, are highly sensitive to numerical choices adopted in these subgrid
models. Using the {\small SMUGGLE} stellar feedback model, we compute idealized
simulations of a $M_{\rm vir} \sim 10^{10} \, \msun$ dwarf galaxy, a regime
where most simulation codes predict significant burstiness in star formation,
resulting in strong gas flows that lead to the formation of dark matter cores.
We find that by varying only the directional distribution of momentum imparted
from supernovae to the surrounding gas, while holding the total momentum per
supernova constant, bursty star formation may be amplified or completely
suppressed, and the total stellar mass formed can vary by as much as a factor
of $\sim 3$. In particular, when momentum is primarily directed perpendicular
to the gas disk, less bursty and lower overall star formation rates result,
yielding less gas turbulence, more disky morphologies and a retention of cuspy
dark matter density profiles. An improved understanding of the non-linear
coupling of stellar feedback into inhomogeneous gaseous media is thus needed to
make robust predictions for stellar morphologies and dark matter core formation
in dwarfs independent of uncertain numerical choices in the baryonic treatment.
