Taking them into handicap stall makes the most sense because they have room to stand and stare at you while you A) make the toilet paper nest upon which to perch or B) attempt the quad-strengthening squat- and-pee.
Of course by this time they have lost all interest in your project and have A) crawled into the stall next to you (no doubt an unwelcome surprise for the neighboring stranger) as you try to grab their clothing or hair and end up peeing all over your shoes and purse OR B) what Baby Boy did today: as I was doing the thing that we do once a month, BB had flicked open the latch on the door exposing my plie-insertion stance to the line of people.
Thankfully, a understanding lady zoomed into action and held the door shut as I finished. Meanwhile BB had managed to drench himself by the automatic sinks.
Is there any question as to why I rarely leave the house?