You'd be surprised. Look up Jurong Island.

To be fair, having an industrial district doesn't preclude tariff laundering either. If you're trying to pass chinese goods as singaporean, you'd want your address to be a factory, rather than an office in a business park somewhere. Even if that wasn't a consideration, at the very least you'd need warehouse space to repackage/reship goods, so you'd need to rent out a warehouse/factory anyways.