use slimefun tag

src/main/java/io/github/thebusybiscuit/slimefun4/implementation/listeners/EnhancedFurnaceListener.java

@@ -18,6 +18,7 @@ import org.bukkit.inventory.ItemStack;
 import io.github.thebusybiscuit.slimefun4.api.MinecraftVersion;
 import io.github.thebusybiscuit.slimefun4.implementation.SlimefunPlugin;
 import io.github.thebusybiscuit.slimefun4.implementation.items.blocks.EnhancedFurnace;
+import io.github.thebusybiscuit.slimefun4.utils.tags.SlimefunTag;
 import io.papermc.lib.PaperLib;
 import me.mrCookieSlime.Slimefun.Objects.SlimefunItem.SlimefunItem;
 import me.mrCookieSlime.Slimefun.api.BlockStorage;
@@ -68,10 +69,11 @@ public class EnhancedFurnaceListener implements Listener {
 
             if (state instanceof Furnace) {
                 FurnaceInventory inventory = ((Furnace) state).getInventory();
+                Material smelting = inventory.getSmelting().getType();
+                boolean multiplier = SlimefunTag.ORES.isTagged(smelting);
 
-                boolean multiplier = inventory.getSmelting().getType().toString().endsWith("_ORE");
                 // In 1.17, the raw ores should benefit from luck multiplier
-                if (SlimefunPlugin.getMinecraftVersion().isAtLeast(MinecraftVersion.MINECRAFT_1_17) && inventory.getSmelting().getType().toString().startsWith("RAW_")) {
+                if (SlimefunPlugin.getMinecraftVersion().isAtLeast(MinecraftVersion.MINECRAFT_1_17) && SlimefunTag.RAW_METALS.isTagged(smelting)) {
                     multiplier = true;
                 }
 

src/main/java/io/github/thebusybiscuit/slimefun4/utils/tags/SlimefunTag.java

@@ -64,6 +64,11 @@ public enum SlimefunTag implements Tag<Material> {
      */
     NETHER_ORES,
 
+    /**
+     * All raw metals in 1.17+
+     */
+    RAW_METALS,
+
     /**
      * All Shulker boxes, normal and colored.
      */

src/main/resources/tags/raw_metals.json

@@ -0,0 +1,16 @@
+{
+    "values" : [
+        {
+            "id" : "minecraft:raw_iron",
+            "required" : false
+        },
+        {
+            "id" : "minecraft:raw_gold",
+            "required" : false
+        },
+        {
+            "id" : "minecraft:raw_copper",
+            "required" : false
+        }
+    ]
+}