Road and track are looking too deep into this. They might have different part numbers, doesn't mean they are different in anyway other than just that, a number. If anything, the internals in the MKV engine might actually be superior to meet Toyota's reliability not the other way around. You would be out of your mind to swap OEM heads, turbo, pistons and rods to new OEM variants for just 47hp specially if they were pretty much identical.
Different cars share the same parts and when you look them up they come with different part numbers. Even the same car but with different MYs have different part numbers here and there even though they are identical. It's been this way forever at least with the Toyota cars I worked with.
My guess is the part numbers are differentiated for inventory management. Each engine is produced with a limited quantity in mind for specific cars and each needs a certain amount of spare parts. If they labeled them all the same, BMW wouldn't be able to differentiate if this parts number was more consumed by this engine variant or the other unless they have different numbers. Or simply to keep stock reserved for one kind of engine in a certain market.
