Sous Vide Scrambled eggs - rapid temp drops when adding pouch

Adding boiling water is definitely a help and it's what I had to do for quite a while to get my sous vide back up to temperature.

You can also let the food come up to room temperature before putting them into the water bath.

Another option which I haven't tried but *should* work is to add more mass to your sous vide rig. If you have ceramic plates or bowls (make sure they are oven or microwave safe, I wouldn't want you to break your fine china) you could add them to the bottom of the water bath as it is heating. They should then help the temperature to recover more quickly, much like a pizza stone does in the oven.

I used a PID controlled crock pot for some time and ran into the same issue. After awhile I began to get a feel for how much the temp was likely to drop and preheated a little higher than target (up to 15F for something big). I had no overcooking problems.

I've recently switched from the 6 qt. CP to a 4 qt. home rice cooker. This heats far quicker as it's 1000 watts vs 300 for the CP. It heats more evenly and efficiently as well. It only gets slightly warm even uninsulated and the aluminum inner chamber conducts the heat MUCH better than ceramic.

I had also the problem with the temperature. And doing it now heating the water 10 Celsius over the final cooking temperature.
My rice cooker is 3.5 qt. none insulated and I had the best result with this. I'm experimenting in the moment with an immersion heater, will see how result this.