Currently, you can add a soft credit when you enter a transaction. After saving, you can navigate to the soft credit and generate an acknowledgment letter from the Edit Soft Credit screen. This workflow takes several steps and could be streamlined...
Adding merge variables in the subject line, especially the FIRST NAME. For an email communications tool, it is an extremely important feature for improving open and click-through rate (CTR).
Create envelope when printing an individual letter
It would be great - upon manually entering a donation or acknowledging a donation to add a print option for the envelope as well - not just the Thank you/Acknowledgement letter.