Hi Pavel,
Have you submitted this to BP for a fix? You're right that it is a simple fix, but no one is going to notice this in this forum post. Let me know if you haven't submitted this request and I'll do so.
The only problem is that the Save Attachments page doesn't take File Pattern/File Name as an input parameter, so as you said it just uses its own default input.
Respectfully,
Dave
Dave Morris, 3Ci at Southern Company