I would like to use Global Data as it is easy to manage per data, but I also need KubeJS advanced feature like editing recipe and loot table, so myu question is :

Do the file from Global Data is loaded after (on top of) KubeJS data (roo/kubejs/data), or it is loaded before (below) KubeJS? Thank you very much, I appreciate answer! :)

Sadly I have no clue, I never tested it together with KubeJS or any similar mod.
But the datapacks are added as early as possible, I'd assume that KubeJS runs it's scripts a bit later.
If you test it, I'd appreciate if you could let me know of the result.

Sadly I have no clue, I never tested it together with KubeJS or any similar mod. But the datapacks are added as early as possible, I'd assume that KubeJS runs it's scripts a bit later. If you test it, I'd appreciate if you could let me know of the result.

I tested it, KubeJS overwriting GlobalPack. It is good, as on my pack I use GlobalPack for premade datapack and resource pack I download from website, while costumized pack I make or edit managed with KubeJS. So it is useful to use both.

Great! Thank you for testing it ^^
I'll close the issue as it's resolved now.