You can tell a difference and the human eye does not see in FPS. This FPS malarky has been going round the internet for years but facts are facts, my experience show you can tell between 60-100-144 and above, I can only test to 144FPS as my monitor is 144hz any fps above this will not be noticable do to the refresh frequency.Cracking the whip won't do much good, this is a unity problem and as such not something TFP have much control over. I'd expect fataal to have made use of the multi-threading job system to speed up pathfinding but that's pure speculation on my part.
Addendum: You won't see any noticable difference above 100fps simply because you can't. The human eye has hardware limitations like everything else.