Not at all clear from the paper whether you need a quantum computer to do these calculations or whether the same circuits could be simulated classically.

(I.e. from what I can see the paper never mentions the amount of entanglement or complexity in the quantum state, or that they used state-of-the-art simulation techniques like tensor networks to check.)

If someone knows of a blog post, supplemental material, etc. that reports this I'd be curious to know.