Very variable depending on what you've been feeding through them and the type of driving.
If there is no smoke or knocking, they are probably ok. If in doubt pull them out and have them tested for spray pattern.
Rev it very slowly from 1400-2000 rpm. Does the shudder disappear or get worse and is there any obvious missing or smoke.
If things improve then it's probably just engine mounts going a bit soft, if it gets gradually worse then it will be an injector either duff or clogged. The r/h mount always goes first due to the extra weight of the turbo and engine torque.
When I tried mine on Veg and didn't drive it for two weeks other than in and out of the garage daily, it did this. Neat injector cleaner sorted it.