[PRQL dev here]

Love what you've done and thanks for building on PRQL!

We're very happy to add something like a PIVOT statement. In the long term, we'd have to think about how to make it work deeply in PRQL, since the column names are suddenly runtime dependent. In the short term, we should definitely make PRQL work for your case — it's important that there's an escape hatch for things that aren't natively supported by PRQL yet. (We have s-strings but I'm guessing they don't cover this specific case?)