We export to Teradata on a regular basis. It would be great to have the ability to append to a table after replacing previously placed data. So the campaign data that was exported yesterday will have it's export date. Todays campaign data will have todays date. If it needs to be re-executed todays data could be deleted but yesterdays would be preserved. Similar to how contact history is stored except that it would be purged. Contact history doesn't store custom attributes at a subject level which is part of why this is sought. This would be a function added to the Append option.
The Truncate table option is to help when writing to a table where the admins have restricted access to the SAS CI Service account to not be able to drop a table. Instead it would truncate it and re-populate. This could be an option as part of Replace (Replace table or Truncate to Replace data in the existing table).