Maybe Frank could earn supporting cast status in Cap's team up book. Or Cap's main title with D-back there, currently, too! As you say, he deserves better than V.F.O.T.W. status A.T.M.
Hope he gets a conversation with Taskmaster in SA, though.
Hey, just saw his wiki entry, what issue was his handbook entry change, that he shares the last name of Devil-Slayer? There's a potential, cronyistic, Schlictastic story seed there.
He was infiltrating the Corporation for Fury, but had a breakdown and lost his memories of who he really was. Which makes him all the more tragic... Frank's really a good man, and a trusted agent of SHIELD that Fury put into an impossible situation and lost to a psychological trauma.
Interestingly, I'd say Devil-Slayer and Constrictor do know each other, through the Initiative and their mutual friend Nighthawk...