I think that it's better to solve difficulty time warp problem in the most obvious and simple way, that is to change the way required work is computed. Currently it is computed as 1/t, that is 15 sec target time is considdered to be 4x more difficult (takes 4x more time) to find solution than 60 sec and this is probably not the case. You (and other bot operators) can do some experiments to determine how required time to find solution depends on target time, then we can construct some function that is good approximation of this dependency and use it instead of 1/t.
Another counter-measure is to add checkpoint, it will prevent whole chain forking.