It's a very small space, with no apparent facility to handle not just #1 and #2, but severe gastric distress. The other passengers then get to look forward to up to 25 minutes in that closed space. There's no stewardess, no way to stop the vehicle. An "emergency evacuation module" shouldn't take much room.
The design incorporates very powerful air compressors and water pumps, and generates, transfers, and isolates a great deal of heat. The cabin will be very well-ventilated, because if it weren't then passengers would die of something other than methane poisoning.
