I ran all my wiring conduits, installed the A/P servo and heated pitot during construction. I found it much easier to do with everything apart, or at least with easy access. I have left the pitot on the wing, and the wings have sat in their stands for about 3 years so I don’t know how much of a drama this becomes at fitment other than being careful.
Van’s website has a sketch of a method for drilling holes for snap bushings or wiring conduit along the main ribs. Many others on here run a conduit through the lightening holes attached to the ribs with a clip. I installed 1/2” conduit for Flyleds tip lights, pitot heater, A/P, and Dynon Thermocouple. There’s plenty of room for more wires to be pulled through if needed. FWIW, I used split corrugated tubing, which was a bit of a pain to pull through, but once installed & pro-sealed is nice and tight, but with access to wires if really needed.
Make sure you install the aileron bracket SB parts during construction - again they’re easy to install when there’s access. They should’ve come with the kit.