I leave my phone in the truck when I have to enter our SCIF. I’m only in there long enough to pick up my gear and Im out. 15 minutes at the most. I hate that place. I don’t spend anymore time in there than I have too. As a contractor I always feel like there is a target on my back so I do everything the same way every time and in the same order. If there is going to be a security violation it isn’t going to be because of something I did or forgot to do.
While on active duty I worked 3 cubicle compartments away from the door to the SCIF for 3+ years and was inside there exactly 5 times and felt exactly as you are describing.