Warm up

Do you need to get the water up to the desired temp prior to putting the meat or whatever your cooking into the pot?

Also, does the cooking time take longer for multiple items vs one? For example if I want a steak medium rare I'd set it at 129 degrees for an hour. If I have 3 steaks should I plan for more time or should I still use one hour at 129 degrees?

I have put steaks in before the water was up to temperature, however, I start the timing from the point it reaches the proper cooking temperature.

Separate bags of steaks cook in the same amount of time as one. THe only exception is if you put them back to back essentially doubling the thickness. It would then take longer for the 2 steaks to heat all the way through.