Curious concept
How the pilot in the loop needs to respond to an engine failure is a simple tracking problem, it should not need cognition, it is push n pull to retain an eye pleasing outcome. On the takeoff, the driver is driving his eyeballs towards a few fixed point at the end of the runway. An engine failure disturbs the vector of the aircraft and gives an error in the tracking task, that the driver responds to, on the ground, that be rudder to return the eyeballs to the desired point in space.
TAC ON or OFF merely reduces the force necessary to be applied, once the pilot has applied an initial input. It works quite well, but after 9000 hours using it, whether it works r not is irrelevant. The pilot response remains the same in the 777 or 787 as it would be in a Pitts in an wind, or a Baron running along the tarmac with varying thrust strings on each engine.
TAC was a nice change to the B767 and 757 and to the 737, where it is nice to have a hand on the rudder trim when flying about the patterns with one blender silent.
For the FNG to the type, ask your IP to run you down the runway and for the IP to vary randomly the thrust levers arbitrarily while the FNG tracks a centreline, or the point at the end of the runway. Same deal airborne sorts out asymmetric flight fairly promptly.
Funny though, having a major thrust loss in the 773 is enough to toss the APLT off, so don't assume that these engines don't bark n bite.