I tried reading this mod's wiki, but there's just not enough meat in there for me to work out how I have to edit the current inky json to make a copy for an item that I want from another mod, and I dont know what im doing wrong but if I try to change the "default" recipe when using shards the game just crashes.

even just having several examples in the wiki of seed json examples would be extremely useful to work out how this mod works.

Without a crash log or a copy of Your changes, I can't help you debug your problem.

As for the docs, I'm not sure what examples would help. The full specification is there and all the required serializers are documented. Only the extra and still WIP stuff is left undocumented.