Schematic illustrating the implications for CDM and SIDM models. Left: collisionless CDM matches subhalo tidal extents but severely underpredicts GGSL. Right: core-collapsed SIDM yields steep inner profiles that match GGSL, but this strongly collisional regime also results in more pronounced mass stripping that significantly reduces tidal extents, even after accounting for the slight expansion of the outskirts due to outward energy transfer during the core collapsing. The inset axes show the run of ﹩\mathrm{log}\rho ﹩ versus ﹩\mathrm{log}r﹩ (not to scale).