With regards to the material used, I have never used or seen waxed linen cord. It was always purely synthetic (plastics) possibly due to cost, availability, or performance.
Only if you are speed lacing and do not knot the intermediate restraints. If there is any chance that you will need to break apart mid line you add a stable knot at each intermediate and can simply break between any tie.
Zip ties are cheaper and faster, velcro might not be cheaper but still faster and a lot more flexible. This being said if I want to send a rover to Mars (so definitely a final install) I will not use zip ties :).
What sometimes happens is that a PHB will see the switch away from lacing and to cable ties and think that the rest of the job is now lower skilled, and they put lower skilled workers on that job. This is bad, because wiring looms are tedious to inspect and test, and we now need better inspection and test to compensate for the lower skilled staff.
Also, because cable tying tends to be done with a hand tool (reproducable tension, uniform cuts, speed of assembly etc) there's a small risk of repetitive strain. I used to use this tool, and it was okay if I was doing the entire loom, but it sucked if I had a big pile of other people's looms and all I was doing was adding cable ties. https://uk.farnell.com/duratool/d03033/cable-tie-gun-stainle...
Here's a link to one model: https://uk.farnell.com/panduit/gts-e/tool-cable-tie-installa...
Good hand tools are always worth the money.