I agree with many of the comments that, yes, there can be too many tweaks.
I have a very dear friend who is constantly buying inexpensive "tweaks" that are supposed do a variety of things, from "blackening the background" to "widening the soundstage" and so on and so on. Often these things pile up and then he’ll call and say nothing sounds right, should he buy new speakers/amps/DAC etc. etc. I advise him to pull out all the tweaks, and he’ll say, "Oh, this sounds much better."
I also agree that you’re better off buying a better-made piece of equipment that doesn’t need a ton of tweaks to sound good. Anything from the power supply of an amplifier to the USB input of a DAC should be designed in such a way as to produce satisfactory results without a lot of junk surrounding it.
I’m generally agin power plants and conditioners and things like that, but with the increasing heat waves here in Southern Oregon, I’ve had to break down and buy a voltage regulator for my tube amplifiers. My wall voltage often drops to 114VAC in the summer and it really affects the amps’ performance. I got a Furman regulator which maintains the voltage at c. 120 volts. I found that it does more good than harm in my system so it has stayed in. Otherwise I really try to avoid a lot of add-ons.