Hey all, custom column data is not accessible via {{ table1.data }} at this time, only, as you mentioned, via {{ table1.selectedRow }}. I've submitted a request for this internally and will keep the thread updated with progress!
In the meantime, the best workaround would be to extract the logic into transformers and have them propagate your custom columns. That way you can reference the transformer instead of the column itself.
I've attached screenshots with 2 transformers and how they're connected to custom columns. Note: i in {{ transformer1.value[i] }} represents the index of the row and maps to the corresponding index of the transformer's array output.
