Currently it's only possible to add custom labels by editing model.json for slice or custom type.
Wouldn't it be better if we could do it through Slice Machine UI instead? It would be easier to set them up and keep track which slice / type is using it.
I completely agree with you! Editing labels manually in the model.json for custom types can be a bit of a hassle, and having the ability to add custom labels through the Slice Machine UI would make things much more convenient. Not only would it be easier to set them up, but it would also make it simpler to keep track of which slice or type is using each label. I'll make sure to add a ping to our feature request list to suggest this enhancement.