Case of elder financial abuse, bank stopped and police contacted and report filed, but all we have on the suspect is a cell phone number (and I am sure a burner phone at that), for a dollar amount between the reporting thresholds: any value to file or no?

There is always value in filing as it get into the database. Whether or not it gets acted upon that is another story.

I am guessing that it is over $5,000 but less than mandatory filing?

Correct.