It also got our submission to CurseForge rejected. As such, I've removed the .jar from the modpack. However, it's easy to add OptiFine yourself: Download the latest Optifine release .jar In the ...

After making a new directory for this sandbox title in the application, you can scour through CurseForge databases to look for the Fabulously Optimized modpack. Locate it, then select Install.