I am shocked if they had no controls. While old "frequency" controls are not needed the number of "on" TX's matters.
I think we have shown in the past that the mega events cause issues. Spektrum DSM2 was especially hard hit, but ALL the major systems had some issues. This certainly makes sense as the noise floor on the band just gets higher and higher.
It would be interesting to see those systems than can log issues (like Spektrum) to see the fades and dropped packets.
I think most of the large events were talking about a system that would limit the number of "on" systems both on the flight line and in the pits.
It will be interesting to hear any issues at IRCHA, if any....