1.12.2 Custom Rewards are Broken, please fix this! I know you probably aren't planning on any future updates, but a quick bug fix would be highly appreciated for modpack creators!

"A quick bug fix update". What makes you think that? 1.12 had just the config option, the reward system was not implemented.

If I'm going to update, I will remove the option as it's not broken, it's not implemented at all.