Well it is open for debate, for example lots of modern diesels have dual mass flywheels DMF, they two jobs 1 smooth out the gearchanges/shock loads to the transmission, and 2 act as a damper for the engine, when the DMF fails lots of people fit solid flywheels in their place, years ago there were many predictions of impending doom/crank failure etc which do not seem to have come to fruition, now whether that would be the same for a crank damper I have no idea.
I think if you can get the part new I would replace it, bearing in mind how rare the 2.4 must be nowadays why risk it.
Thanks for the input. At least some peace of mind i did not find one. Take a look at the youtube here and it seems the guy is confidence on the issue too.
Fix a broken Crankshaft Pulley Harmonic Balancer Repair | Honda Acura | Toyota Lexus | Bundys Garage - YouTube