In ΛCDM, the large-scale velocity field and time-evolving gravitational potentials that generate the Integrated Sachs–Wolfe (ISW) and kinetic Sunyaev–Zel’dovich (kSZ) effects should be statistically isotropic and well described by linear theory, so velocity and potential “templates” built from galaxy surveys ought to align cleanly with CMB maps apart from noise (Ho et al. 2009; Sherwin et al. 2012). In practice, directional reconstructions of ISW and kSZ signals show uneven sky coverage, anisotropic amplitudes, and mismatches between template-predicted and observed features, raising questions about whether the assumed ΛCDM velocity field, growth history, and isotropy are sufficient, or whether unmodelled systematics or more complex large-scale dynamics are at play (Keisler & Schmidt 2013; Ruiz-Lapuente et al. 2019).