How to make a Rust loot multiplier plugin (Oxide/Carbon)

using System.Linq;
using System;
using System.Collections.Generic;
using Newtonsoft.Json;
using Oxide.Core;

namespace Oxide.Plugins
{
    [Info("Loot Multiplier", "RustPluginGenerator", "1.0.0")]
    [Description("Multiplies stackable items spawned inside loot containers with overrides and a blacklist.")]
    public class LootMultiplier : RustPlugin
    {
        private const string PermAdmin = "lootmultiplier.admin";

        private PluginConfig config;

        private class PluginConfig
        {
            [JsonProperty("Global Multiplier")]
            public double GlobalMultiplier = 2.0;

            [JsonProperty("Ignored Shortnames")]
            public List<string> IgnoredShortnames = new List<string>
            {
                "rifle.ak",
                "rifle.lr300",
                "rifle.bolt",
                "rifle.semiauto",
                "smg.2",
                "smg.thompson",
                "smg.mp5",
                "pistol.semiauto",
                "pistol.m92",
                "pistol.python",
                "pistol.revolver",
                "shotgun.pump",
                "shotgun.double",
                "shotgun.waterpipe",
                "lmg.m249",
                "rocket.launcher",
                "explosive.timed",
                "explosive.satchel",
                "grenade.f1",
                "tool.camera",
                "hammer",
                "building.planner",
                "box.repair.bench",
                "toolgun"
            };

            [JsonProperty("Item Overrides")]
            public Dictionary<string, double> ItemOverrides = new Dictionary<string, double>
            {
                ["scrap"] = 3.0,
                ["wood"] = 5.0,
                ["metal.fragments"] = 4.0
            };
        }

        protected override void LoadDefaultConfig() => config = new PluginConfig();

        protected override void LoadConfig()
        {
            base.LoadConfig();
            try
            {
                config = Config.ReadObject<PluginConfig>();
                if (config == null) throw new Exception();
            }
            catch
            {
                PrintWarning("Configuration file is invalid, using defaults");
                LoadDefaultConfig();
            }
            SaveConfig();
        }

        protected override void SaveConfig() => Config.WriteObject(config);

        protected override void LoadDefaultMessages()
        {
            lang.RegisterMessages(new Dictionary<string, string>
            {
                ["NoPermission"] = "You do not have permission to use this command.",
                ["Status"] = "Loot multiplier: global {0}x, overrides: {1}, blacklisted: {2}.",
                ["Reloaded"] = "Loot multiplier configuration reloaded."
            }, this);
        }

        private string Msg(string key, string userId = null, params object[] args) =>
            string.Format(lang.GetMessage(key, this, userId), args);

        private void Init()
        {
            permission.RegisterPermission(PermAdmin, this);
        }

        private object OnLootSpawn(LootContainer lootContainer)
        {
            if (lootContainer == null || lootContainer.inventory == null) return null;
            if (config == null) return null;

            var items = lootContainer.inventory.itemList;
            if (items == null || items.Count == 0) return null;

            foreach (var item in items)
            {
                if (item == null || item.info == null) continue;
                var shortname = item.info.shortname;
                if (string.IsNullOrEmpty(shortname)) continue;
                if (config.IgnoredShortnames != null && config.IgnoredShortnames.Contains(shortname)) continue;

                double multiplier = config.GlobalMultiplier;
                if (config.ItemOverrides != null && config.ItemOverrides.TryGetValue(shortname, out double ov))
                    multiplier = ov;

                if (multiplier <= 1.0) continue;

                int original = item.amount;
                int maxStack = Math.Max(1, item.info.stackable);
                int scaled = (int)Math.Floor(original * multiplier);
                if (scaled <= original) continue;
                if (scaled > maxStack) scaled = maxStack;
                if (scaled == original) continue;

                item.amount = scaled;
                item.MarkDirty();
            }

            return null;
        }

        [ChatCommand("lootmult")]
        private void CmdLootMult(BasePlayer player, string command, string[] args)
        {
            if (player == null) return;
            if (!permission.UserHasPermission(player.UserIDString, PermAdmin))
            {
                SendReply(player, Msg("NoPermission", player.UserIDString));
                return;
            }

            string sub = args != null && args.Length > 0 ? args[0].ToLowerInvariant() : "status";
            if (sub == "reload")
            {
                LoadConfig();
                SendReply(player, Msg("Reloaded", player.UserIDString));
                return;
            }

            int overrideCount = config?.ItemOverrides?.Count ?? 0;
            int ignoreCount = config?.IgnoredShortnames?.Count ?? 0;
            double global = config?.GlobalMultiplier ?? 1.0;
            SendReply(player, Msg("Status", player.UserIDString, global, overrideCount, ignoreCount));
        }
    }
}