Junk and snake oil it seems.
I would agree with this having done mine but I thought I saw a video of them building the harness by hand so in our car cases they were done by hand. Someone who does this all the time though would still be much better than myself. I should have fixed only the injectors as the boots were very bad. Plus now I don’t really trust any of them unfortunately
I happen to have the head monsters noel lee's old 355. And it had all this ****ty speaker wire i ripped out, the funny thing was they put fat monster cable wires to the speaker but spliced cheap wires hidden in the dash to the head unit. He had an awesome old school pioneer high end head unit to make the sound good, but the wires did very little benefit
I fell for it and it’s been 15 years and no problems But likely no problems without it. you will have more problems by being sloppy when you pull the engine and stretch the harness. My advice is fix things as they break and gold is likely over rated