EMC values should be in a datapack so that mod (and modpack!) developers can easily add EMC values without having to touch your mod or your APIs.

If you point me in the right direction, I will extract the values to a JSON format and send it to you.

Is it impossible with config/itemalchemy/emc_config.json?
I know nothing about datapacks.

It is possible to do it there, but it's much more difficult to ship a config file with another mod. I'll work on PRing data pack support.

I tried to manage EMC with "data/", how is it?

that seems like exactly what i was hoping for, i'll mess with it later today once i'm on my laptop