Shielded power cable for Nucleus

I need an answer
From the previous posts I get that only the last meter matters and not the lot of meters of unshielded cables in my wall.
Must it be exactly 1 meter? Or would be 0,5 meters enough?
To save money I could use the same cheap cable I have in the walls to get near my devices and only use an expensive shielded cable for the last … say 0,01 meters.
Did I benefit from the big sq improvements or is it important to use the whole meter?