Experiments to measure the size of the electron consists on colliding two beams of electrons against each other and counting how many are scattered and altered their trajectories.
By counting the collisions, and knowing how many particles we have thrown, we can estimate the average size of each particle in the beam.
Up to the highest energy of the electrons reached in the LEP experiment at CERN, the estimated size of the electron is below 10−19 m.
This is consistent with our point-like structure for the CC, because the radius R is six orders of magnitude larger than this value.