The legacy mods are a little limited compared to Ragnarok and Macro due to the fact the RS and A Button can't be used in the mods. About the only mod missing from legacy controllers that the legacy controllers are capable of doing is zombie auto aim (though you can sort of do it anyway by using rapidfire on the left trigger)
Edit: Oops, also hybrid optic rapidfire glitch is missing from legacy. Am I missing others that the legacy would be capable of?
Ragnarok got some love, it seems like Legacy ought to be the next one to get an update.