I think in this situation, cgtrader should not refund. If customer wants to buy a model for use in software, which support is not mentioned in description, at least he should contact the seller before purchasement and ask for assistance, otherwise we risk to end up in situations when customer buys a regular model and complains that it can't be 3D-printed, or vice versa - one buys printable model and asks for refund, because the model is not UV mapped.