I know even in Kansas you can petition to attend Sr Nationals if you did not make the finals. I am not sure of the criteria for this to be approved. It particularly makes sense when often the toughest matches are in the semis due to the way our state brackets are set.
Great example was when Dante Rogers of Wichita NW lost to Nathan Furches of Derby in the semis and had to battle back and take 3rd. Rogers petitioned and then took 5th at 103 Senior Nationals.