I don’t think I said anything about prompts, tooling, or harnesses.
The model itself should not be substituted(for example, quantized) without an explicit SKU change.
It isn't though.
They should let you use your subscription with your own harness. Until they do, you're just borrowing someone else's workflow, which is liable and likely to change whenever the fellas over at Anthropic get a wild hair and decide to introduce a new experiment.