  We implement coherent delocalization as a tool for improving the two primary
metrics of atomic clock performance: systematic uncertainty and instability. By
decreasing atomic density with coherent delocalization, we suppress
cold-collision shifts and two-body losses. Atom loss attributed to Landau-Zener
tunneling in the ground lattice band would compromise coherent delocalization
at low trap depths for our $^{171}$Yb atoms; hence, we implement for the first
time delocalization in excited lattice bands. Doing so increases the spatial
distribution of atoms trapped in the vertically-oriented optical lattice by
$\sim7$ times. At the same time we observe a reduction of the cold-collision
shift by 6.5(8) times, while also making inelastic two-body loss negligible.
With these advantages, we measure the trap-light-induced quenching rate and
natural lifetime of the ${}^3$P${}_0$ excited-state as $5.7(7)\times10^{-4}$
$E_r^{-1}s^{-1}$ and 19(2) s, respectively.
