If you have long strings of cubes, consider putting in your own power pole/s, to provide a seperate access to the the cubes. This will reduce the length running next to the power. Make sure and label them Data only, I have seen electricians run power down them, since they are there.
Also running the cable down the main wall to the cube, then turning down the shorter walls will put the jacks outside the EMF field generally. The power outlets are most often on the main cube wall. Installing the power pole/s at the end of the cube run will come into the raceway, many times, before encountering any shared path with the power to that point.
It may add some time, amd cost, but let the customer make that decision, then you have covered your self, if there is any issue with interference.
I would not worry much about it, unless the runs are long, and the cube wall is long as well.
You do not always get what you pay for, but you never get what you do not pay for.