our Standard model all CE events with HG donors lead to a prompt merger before a DCO binary is formed, regardless of the aforementioned energy balance.

The model employs a Maxwellian distribution of natal kicks for NSs with 1-D root mean square velocity $\sigma=265$ km/s, consistent with NS observations [@hobbs]. The same distribution is extended to BHs, where we allow for the possibility that the kicks may be reduced due to fallback of material during the SN that leads to BH formation. The reduction in BH kicks is described via $$\label{vkick}
V_{\rm k}=V_{\rm max}(1-f_{\rm fb}),$$ where $V_{\rm k}$ is the final magnitude of the natal kick, $V_{\rm max}$ is the velocity drawn from a Maxwellian kick distribution, and $f_{\rm fb}$ is a “fallback factor” that depends on the amount of fallback material, calculated according to the prescription given in [@chrisija]. Our Standard model uses the “Rapid” convection-driven, neutrino-enhanced SN engine [@chrisija]. The SN explosion is sourced from the Rayleigh-Taylor instability and occurs within the first $0.1\,$–$\,0.2\,\mbox{s}$ after the bounce. When used in the context of binary evolution models, this SN engine successfully reproduces the mass gap [@massgap] observed in Galactic X-ray binaries [@mg1; @mg2], but see also [@2012ApJ...757...36K].

*2) Optimistic 