The day has come. The new, fixed version of the mod can now be downloaded in the same mod page and used.

Note: The mod file and name in-game will be called SP plus instead of SP Extra, but I will still refer to it as SP Extra

Just a quick warning: Before doing anything else, PLEASE delete the old mod from the mod folder. I can't stress this enough, while the game will treat it as a different mod from the old version, having both of them on at the same time will cause the mod to break, not being able to even load the parts in the designer.
I don't know why it does this, but in order to avoid this you MUST delete the old version before downloading the new one.

Here is the link to the mod page: MOD PAGE