In One Punch Man manga chapter #168,
Saitama returns to the past and fuses with his past self. His clothes also fuse, so the naked Saitama by fusing with the dressed Saitama appears with a suit which is half complete, with a hole in his private area. So if Saitama (human/organic) and clothes (inorganic) fuse with their former versions,
Why didnt Genos' core fuse with its past version?