is not important to consider one method as ‘more accurate than another’, but the difference should be kept in mind when comparing results between studies.

For nuclei of atomic number $A$, the coalescence model predicts a production rate $R(A) \propto p_0^{3(A-1)}$, making [$^3\overline{\text{He}}~$]{}predictions particularly sensitive to nuclear physics uncertainties. The choice of coalescence momentum is known to have significant dependence on the details of the underlying scattering process and is measured to be larger for $A=3$ than $A=2$ [@heavyion]. While heavy-ion collisions provide the only available constraints on [$^3\overline{\text{He}}~$]{}production, they do not resemble the dynamics of dark matter annihilation. In an attempt to bracket the effect of this uncertainty on the resulting [$^3\overline{\text{He}}~$]{}spectrum, we derive values for the $A=3$ coalescence momentum, $p_0^{A=3}$, using two different methods. In the first method, we choose to scale the antideuteron coalescence momentum, $p^{A=2}_0$, up to $p_0^{A=3}$ following the theoretically motivated scaling of Ref. [@salati1997], in which $p_0 \sim \sqrt{B}$ for total nuclear binding energy $B$: $$\begin{aligned}
    p_0^{A=3}=\sqrt{B_{^3\overline{He}}/B_{\bar{D}}}\ p_0^{A=2}=0.357\pm 0.059 \text{ GeV/c.}\end{aligned}$$ As a second method, we use heavy-ion results from the Berkeley Bevalac collider which fit [$\overline{\text{D}}~$]{}, [$^3\overline{\text{H}}~$]{}, and [$^3\overline{\text{He}}~$]{}coalescence momenta for several collision species (C+C up to Ar+Pb) at incident energies from 0.4-2.1 