You can now block certain items/fluids from being stored and crafted with using a tag. Add the tag ae2:blacklisted/storage to any item/fluid to blacklist it.

KubeJS Examples

// Item Blacklisting
ServerEvents.tags('item', event => {
   event.add('ae2:blacklisted/storage', 'minecraft:stone'); 
});

// Fluid Blacklisting
ServerEvents.tags('fluid', event => {
    event.add('ae2:blacklisted/storage', 'minecraft:water');
});

Note: Please refer to the KubeJS docs on tags for more information on syntax and adding tags.