It turns out you actually don’t need to modify any files to work around this issue. Just re-enable auto-ignition and make sure you still have controls mapped for ignition and starter. When you click the right “arrow” button and enter the cockpit in a practice or qualifying session, just immediately use your ignition control to turn the car off. You can now sit as long as you want watching the HUD to judge when you want to exit pit lane. I know this is probably “captain obvious” material. I just wanted to mention it in case anyone else had it stuck in their head like I did that the auto-ignition setting was the only way to sit in the cockpit at the beginning of practice and qualifying and not have the engine running. It's pretty easy to forget you can use the individual ignition control to turn the car off.