Another thing, the one area where you could have extra capacity without too much of a weight penalty would be engine size.
No doubt they'll get it figured out in a timely manner. That's the great thing about private enterprize!
A friend who was working in the design and engine testing phase said that it was a very deliberate choice to go with more engines/smaller engines exactly for the reason of what happened today. The ability to abort the launch AFTER engine start. This is the largest engine they can make that can reliably be shut down after ignition and initial rev up of the engines.
An uncontrolled engine is a constant fear among the designers; the launch vehicle depends upon exact control of all engines throughout the initial launch. If I recall correctly, it's less than a few thousand feet after clearing the tower that the launch vehicle can compensate for engine failures of up to seven of the nine engines and remain in controlled flight.