  We study the kinematics of the interstellar medium (ISM) viewed "down the
barrel" in 20 gravitationally lensed galaxies during Cosmic Noon ($z=1.5 -
3.5$). We use moderate-resolution spectra ($R\sim4000$) from Keck/ESI and
Magellan/MagE to spectrally resolve the ISM absorption in these galaxies into
$\sim$10 independent elements and use double Gaussian fits to quantify the
velocity structure of the gas. We find that the bulk motion of gas in this
galaxy sample is outflowing, with average velocity centroid
$\left<v_{cent}\right>=-141$ km$\,$s$^{-1}$ ($\pm111$ km$\,$s$^{-1}$ scatter)
measured with respect to the systemic redshift. 16 out of the 20 galaxies
exhibit a clear positive skewness, with a blueshifted tail extending to $\sim
-500$ km$\,$s$^{-1}$. We examine scaling relations in outflow velocities with
galaxy stellar mass and star formation rate (SFR), finding correlations
consistent with a momentum-driven wind scenario. Our measured outflow
velocities are also comparable to those reported for FIRE-2 and TNG50
cosmological simulations at similar redshift and galaxy properties. We also
consider implications for interpreting results from lower-resolution spectra.
We demonstrate that while velocity centroids are accurately recovered, the
skewness, velocity width, and probes of high velocity gas (e.g., $v_{95}$) are
subject to large scatter and biases at lower resolution. We find that
$R\gtrsim1700$ is required for accurate results for the gas kinematics of our
sample. This work represents the largest available sample of well-resolved
outflow velocity structure at $z>2$, and highlights the need for good spectral
resolution to recover accurate properties.
