public class InventorySystem : MonoBehaviour
{
    [SerializeField] private ItemData[] _itemData;
    private const float MaxFrameDelta = 1.0f / 30.0f;
    private Dictionary<ItemData.ItemId, ItemData> _itemMap = new();

    private IEnumerator BuildItemMap()
    {
        var stopwatch = new Stopwatch();
        stopwatch.Start();
        foreach (ItemData item in _itemData)
        {
            _itemMap[item.ID] = item;
            
            // Build as much of the dictionary as possible before yielding to next frame
            if (stopwatch.Elapsed.TotalSeconds > MaxFrameDelta)
            {
                yield return null;
                stopwatch.Reset();
            }
        }
    }
}