Hey Brassarrow,
you are right, I just realized Greg in fact wrote “wire extensions”, I missed that when reading for the first time. I did not mean wire extensions, just extended wires.
(if you know me you know what I think of these Cable Connectors Used on the Onefinity, I wrote about it here so of course I would never recommend to add more of them 
)
Greg, sorry my fault, I meant:
a longer Aluminium and more drag chain links for the X rail, and (new) extended wires for Z stepper and for the router.
Also if you ever plan to use a spindle you should plan a thicker cable of up to 12 mm diameter, perhaps two 8 mm water cooling hoses, a thinner cable for a light that some people put around the spindle, maybe sensor cables for upgrading to inductive proximity sensors as limit switches, all in all with a drag chain of 15 x 50 mm you are safe for any later additions, but I have seen many are satisfied with 15 x 40 mm, or 15 x 30 when using air-cooled spindle.
Also since these cables are moving cables, there always should be a strain relief at the begin and the end of every drag chain, this prolongates cable life. I’ve seen that it is often omitted in a DIY environment. Also spacers between each cable/hose helps prolongate cable life.