I think that this is hard to implement, but will you add recipe compatibility between mods in Mcreator 2?
Here is how I think it should be added:
There is a button in the workspace window called "export mod element id". When pressing this button Mcreator will ask you the name of the modification, then it will create a file where is stored the code for adding compatibility to that mod element.
You can only export Blocks, Items, Tools, Food, Ranged Items and (maybe) GUIs and Dimensions.
There is also a button for exporting all the mod elements at the same time (each one in a different file) (the names of the files will be the same of the mod elements).
Then there should be a button for importing mod elements id files. This way, in a different workspace, you can use items from other mods in recipes and procedures.
When adding an item to a recipe, there should be the "imported mod elements" as new filter.
Users can share a zip where there are all the files for allowing the creation of addons.
I'm not a coder, but if this can be done by simply copy+pasting a text id, then there should just be a button for copying the id of a selected mod element and a button for adding an id to the workspace (a window where an user writes/copies+pastes an id).
Then there should be a window where the user can see, edit and remove all the imported ids.
Sorry for bad explanation :(