Hey I added this little feature to my local version of this script and thought it would be useful. Basically you give a list of item skin IDs and it skips them and doesn't apply the sort button to those specific items, helpful if you have specific skinned items doing differents things then storage would normally do.

New config property, using default entry of 0 to not affect any skins

[JsonProperty(PropertyName = "Skip Skins", ObjectCreationHandling = ObjectCreationHandling.Replace)]
public List<ulong> Skins = new List<ulong>() { 0 };

and in the "OnLootEntity" hook just add the following before creating the button

var baseEntity = storage as BaseEntity;
if (_configData.Skins.Contains(baseEntity.skinID))
	return;

I have been working on a new major release of the plugin which adds a feature that accommodates this use case.

https://umod.org/community/sort-button/43739-sort-button-20-beta

Please consider trying the beta and let me know whether this solution is adequate.

Here is an example of how you would enable/disable the button for a specific skin ID (Enabled -> false is the relevant bit).

"Containers by skin ID": {
    "1234567890": {
      "Enabled": false,
      "OffsetX": 476.5
    }
  }