While I’m sure there will be more added through the cash shop, there are currently only 6 insignia available via Penances. One for completing 50 missions on each class and two for Scab kills (not sure why Dregs and Pox don’t get Insignia for their Penances). Compared to 25 Frames (many of which are simply less ornate versions of each other), this leads to a severe lack of variety between players.
Consider balancing this out more or adding further upgraded insignia beyond 50 missions for each class.