How Do Host.json and Azure App Settings Differ for Function App Configuration?

Just throwing it out there—are you sure about the environment variable limits? I've read that for some logging settings, they can merge between `host.json` and environment variables, but it looks like that doesn't apply to those trigger configurations.

Actually, you can override some service bus trigger settings through environment variables, so it’s worth checking for Cosmos triggers too. It might not be the same for every scenario, but you could find some customization options.

In Azure Functions, `host.json` is used for function-runtime configuration, so it defines how the Functions runtime behaves for your app. For parameters like `MaxBatchSize`, `PollingIntervalMs`, and `MaxChangesPerWorker`, those must go into `host.json`, particularly under the Cosmos DB section. They aren't read from environment variables.

On the other hand, Azure App Settings work as environment variables and are typically used for things like secrets and connection strings, not for controlling runtime behavior. So, just to clarify, you can't set those trigger tuning values in App Settings, as they wouldn't be recognized by the runtime.