If you're concerned about data retention, you'd want to select an inference provider that is listing 'ZDR' (zero data retention) as a feature.

For example, a lot of the Chinese open weight models have become quite capable and because their weights are available end up like generic vs brand name medicine where there's multiple providers serving them with different production conditions.

Because enterprise use will often be worried about data retention or sending data to China, the alternative providers usually offer things like US-only inference or zero data retention.

If you're not going to use it all that often, a la carte API use is going to be way cheaper than a subscription, probably better results than a free plan with a closed model provider, and give you more control over the process.