Any bracing you can add will help. It's not going to fold up with just a floor pan removed. I have a uni body jig that clamps the cars I work on at the rocker pinch welds and has vertical posts that brace structural control points on the car. You can get some metal, wood, Jack's (that don't lose pressure) to support the car in critical areas. You don't need to get too crazy with just the front floor section.
