I believe private smart contract should be possible. Specifically, inputs and outputs of a state machine could be blinded, but verified where the computation output is also blinded (and therefore only known to the sender and receiver of a transaction)
Private smart contracts are possible and there are many corporate organizations including Walmart are using it. A simple implementation could be found here:
https://github.com/paritytech/wiki/blob/master/Demo-PoA-tutorial.md Is anyone aware of any project using blinding factors for input/output state machine manipulation? (Not asking about and altcoin, please do not shill)
Well, you'd not really know if they're using it privately. Like I mentioned above, Walmart uses it to verify its Food-Supply chains and that's all the info they're released.
Apart from that ShadowETH, Enigma and Arbitum are also great examples of Private smart contracts. So yes, like you said, not only possible, its already available for corporates and individuals as SaaS products. And I am sure of ShadowETH and Arbitum having input/output state machine manipulation. Check them out.
