Thanks WarpedOne. Can anyone else verify this? Not being engineer, I have no idea how big a change it would take to change the doors.
As a mechanical engineer if someone told me after the Model X preview I needed to make regular doors an option I would tell them it can't be done.
If someone told me they wanted falcon doors as an option to regular doors from day one I would probably be disbelieving and tell them it will make both doors bad.
Technically I think it would be easier to put regular in the giant holes of the falcon doors but you would get some weird roof insert panels (that would cost a lot to install in the line) and probably inserts on the other 3 sides of the Falcon doors. Then put a smaller weird shaped door between all the inserts. It wouldn't be pretty, probably cost more than the falcon door. If they did this. In my opinion it would be a disaster, unless it was planned from day one. If planned for from the beginning I bet you still end up with weird shaped regular doors and a funky surrounding.
My gut is everyone is getting the falcon doors. If YOU don't get falcon doors neither will anyone else, and it wont be a decision.