[UncleEntity]

I know in blender there is a compile time check to ensure the structs are properly packed and it has nothing to do specific memory layouts.

I think it has to do with reading/writing them to disk but honestly never cared enough to ask anyone. Did make things convenient sometimes when you could ‘steal’ a padding value and magically got backwards compatibly because the older versions just ignored that field (and when reading an older file just set it to a sane default).