> chips built on their process node were materially worse

Would they be considered the same chip in the same design? Or same chip with slightly different design? Or different design altogether?

Genuinely curious because sometimes to support both Windows and Linux code would need to follow OS distinct paths in many locations even if the compiler is supposed to support cross arch, resulting in binaries that are supposed to be the same but behaves differently due to necessity. Is this the case here? Does TSMC and Samsung support different format of chip design equivalent of code?

Most likely: Same design, marketed as the same chip. Might see differences in power consumption and thermals but not in a way that will affect normal users. Apple has relatively few designs that they use across different products so that would further mask differences. If the Intel-fabbed variant of a chip ran 5% hotter but Apple put it into Apple TV then basically nobody would notice or care.