Hello , i did had to add 2 lines in plugin for it to display skins for items in loottable . if your skins dont work add in line 1415 following 

item.skin = amounts.skinId;
item.name = amounts.displayName ?? string.Empty;

so it becomes :

if (lootTables.LootTables[type].UngroupedItems.TryGetValue(item.info.shortname, out LootAmount amounts))
item.amount = UnityEngine.Random.Range(Math.Min(amounts.Min, amounts.Max), Math.Max(amounts.Min, amounts.Max)) * _config.Loot.lootMultiplier;
item.skin = amounts.skinId;
item.name = amounts.displayName ?? string.Empty;

item.OnVirginSpawn();
return item;