A fast re-alignment will correct your position to the one entered, but the drift rate of error will remain since it is a function of time. In other words, your helping the system temporarily, but your position accuracy is deteriorating at the same rate. This can only be fixed by a completely new alignment. If your system shows you the ANP-value, you can observe the trend. I always did a complete alignment whenever the groundspeed on the stand showed more than 3 kts.
Cheers, Magelan