All Signal/comms and power wiring need common mode chokes?

[cupoftea]

Supposing you have a small system around 50cm by 70cm by 50cm height.
It has multiple PCBs in it. The enclosure is plastic. There is an offline 20W flyback SMPS in it. Also a few DCDC buck converters.
There are multiple wires and cables going from board to board, carrying power rails, comms signals, and general signals which are just sometimes permanently high or low.
I have never tried to get away with not having common mode chokes at every single cable entry/exit from any board. Do you think its possible to get away without using common mdoe chokes on some of the lines?
..speaking from a radiated emissions point of view...ie passing EN55032

Which is the best common mode choke family for RS485 going off the board from a connector?

 

[Technitab]

Noise suppression on lines with high current flows, such as AC/DC power supply lines, is best achieved via common mode choke coils. The frequency distortion is reduced. Noise suppression on lines where signal waveform distortion is a problem, such as a video signal lines, is best achieved with common mode choke coils.