While I don't actually do any forensics work, occasionally I've been asked to acquire a drive image along with an MD5 or SHA-1 checksum. Perhaps adding in a --forensic trigger (even if it's in the paid version) would be really awesome. Even if it just created a log file at the end with the drive's model and serial along with date & times imaging was performed along with the checksums and perhaps a list of unread blocks.
It might be a nice selling point for the paid version over the free.
It might be a nice selling point for the paid version over the free.