Defensive Coordinator, Josh Boyer appears to have a real good eye for identifying potential CBs that fit the system. (Don't forget that Boyer had 13 years under Belichick - he too has been trained by the best). He developed Malcolm Butler from an undrafted free agent from West Alabama to a key player in New England where he helped win a Super Bowl. He also saw something in Nik Needham last year in Miami, was actively involved in recruiting him from the University of Texas - El Paso Miners and after a mediocre start, had him competing really well towards the end of the season. Best pleasant surprise of 2019.
If Boyer and Coach Flo see something in Borders (a player I had never heard of), then let's see what the kid has. There's nothing to lose. BTW - Borders was educated at Duke - so he's probably quite bright. However, after 6 other teams have previously signed and then cut him, it's probably unlikely that he makes the roster. Raheem Mostert type reclamations are possible but rare.