The default sync mode is set to "full refresh", but hoping to use "incremental - append" for all streams where this option exists without manually changing it for hundreds of streams. Is this possible?

Hmm, I don't know enough to give you a confident answer yet. The extracts provided do not contain information on how to set "Incremental - Append" as the default sync mode for all streams in Airbyte. However, it's important to note that different sources and destinations support different sync modes. For example, the [Google Ads source connector](https://docs.airbyte.com/integrations/sources/google-ads) and the [Salesforce source connector](https://docs.airbyte.com/integrations/sources/salesforce) support "Incremental - Append" and "Incremental - Append + Deduped" among others. On the other hand, the [S3 destination](https://docs.airbyte.com/integrations/destinations/s3) supports "Full Refresh Sync" and "Incremental - Append Sync", but not "Incremental - Append + Deduped". For more detailed information, you may want to refer to the Airbyte [documentation](https://docs.airbyte.com/understanding-airbyte/connections/) on connections and sync modes.