Pregnant women are not supposed to change litterboxes due to toxoplasmosis, which is transferred from a cat's bowels into their poop. It has nothing to do with urine & ammonia, therefore has nothing to do with supporting your theory in this thread.
We have a litterbox in the laundry room less than 9 feet from our tank and 0 ammonia in that tank or the RO/DI water that gets made in the laundry room. At times the cat will move all the litter to one end of the box & pee in the empty side, which is the only time there's an ammonia smell in the house. One tilt of the pan fixes that. We still have no ammonia in the tank. Box gets scooped on trash day once a week & changed completely once a month. Still no ammonia in the tank or water.