I think the contract and the end user licence agreement is your best bet in terms of IP.

Some time ago I have read some research from Bocconi that concluded that very few industries (like pharma) are happy about how IP protect their competitive advantage. So my suggestion is to think about how to protect competitive advantage not intellectual property.

Even if you don't deploy the model on your customer hw you still have the risk that the model can be used "as a service" to create a synthetic dataset by a competitor (this is one of the risks my team is worried about).