^A Kzinti also appeared on the Elysian Council in TAS: "The Time Trap"
The Next Generation novel The Captain's Honor
had a Kzinto sub-plot, although they had their name changed at the last minute to "M'dok". IIRC (and it has been a long time since I read it), they retconned the Man/M'dok wars down to two wars, one pre-Federation and one post.
I find the idea that the Federation may be occupying Kzin, forcing these natural predators to live peacefully (as was going on with their Ringworld equivalents), quite fascinating. If Kzinti territory is/was in the heart of the Federation, they would have to be controlled to some degree to ensure the safety of the core Federation worlds.