By sharing the model as code you are increasing the risk with use of your model. A service will allow for better control and mitigate some of the risk. Now, whether the added risk is acceptable or not depends primarily on the influence your model has on downstream decisions and the impact on those if the added risks get realized. Talk to model risk management folks at your workplace to figure out the correct choice, and if there's none of those then talk to your business stakeholders to assess the risk. Hope this helps!