Briefly, I distinguish between the myriad of tweaks outside the signal path, and products/methods that touch the power and signal paths. I am unusual in the industry, as I recommend the proper way to use and assess cabling is with entire looms/sets from the manufacturer. So, my comments on cables are almost always in the context of that methodology.
To that end, I have found the efficacy of aftermarket cables to be not debatable when used in sets. I also consider them a component as such, and continuously in personal listening and reviewing they confer as large changes as components - again, when used in sets. Changing a cable here and there ad hoc without a thorough understanding of the manufacturer's intended sound is largely fooling around, a waste of time in that it yields no direction to push the system toward a desired result.
That use of cables is very much like using tweaks; no directivity and nothing more than hopefulness of a good result.
If you have not yet worked with aftermarket cables, I encourage you to read my reviews of cables, wherein I explicate my methods. You would perhaps enjoy my latest review of the Iconoclast Cables published at Dagogo.com. For someone who is not yet ready to trust the system, to part with more significant numbers of dollars to test it out, the Iconoclast Cables are ideal, because they use the same geometry, AWG, etc, but with a different conductor for each level of performance. That is not very common in the HiFi cable industry.