I understand how modular sets work. But what I’m confused about is the size some of them tend to be. I see some modular pieces, like a wall for example, that might be 4x4 meters. This maps a 2k texture nicely with a texel density of 5.12 per meter. But then I see some slightly taller. Or I see some like 3x4. Is there any…
Powers of two rule is only for bitmaps. Not for models. It's nice to have consistent texel density, but in practice it is difficult/impossible to maintain. It is not a strict rule, it is a "nice to have". Wall thickness is best matched to your grid, just to make it easier to align/snap pieces. That's it.