Even with auto-save enabled on the batch template, batches of downloaded from BBIS do not auto-save, regardless of the transaction type.
We are currently evaluating this issue for a fix in a future service pack.
Steps to Duplicate
1) Create an Enhanced Revenue Batch template and enable auto-save. 2) In Web > Manage Web Transactions > Batch Assignment Settings > Add a donation assignment using the batch template from step 1. 3) Download a BBIS transaction into that batch. 4) Go to the batch properties and notice that auto-save is not enabled. 5) Go to batch entry and manually add a batch using the batch template from step 1. 6) Notice that it auto-saves.