How important is it that all cables come from the same manufacturer?

I was a real mix and match guy, now not so sure, Had a Cardas Golden Presence in a Golden Reference signal chain, and swapping to a Reference gave me far more of an improvement than I would hear If I A/B’d these two in system consisting of foreign cabling.

Quite unexpected, as these two cables are very similar, with only minor changes to shielding and construction

The OCD in me loves having everything match, but that is just aesthetics.     

In practical terms I am not sure it matters at all.

sometimes it's simply how much time we want to spend buying/selling/shipping and listening to different cables...there are so many good brands and models out there...

     PCs: Five Zu Mothers (preamp, phono pre, CDP and two tubed main amps), Zu Bok (TT to SDS), two Synergistic Master Couplers (SS subwoofer amp and power purifier/distribution, both direct to AC outlets)

     Interconnects: two SR Tesla Apex (mains), Kimber Select (KS1030s on phono pre and KS1130s on CDP), SR Tricon Analog (TT)

     Speaker cable: Analysis Plus, Big Silver Oval (mains), Kimber 8TC (subs)

     The above were all cycled through, with a wide variety of Wireworld, Audio Magic, Cardas and Audioquest offerings, over the years, for comparison and found to deliver the least colored and most open presentation (sound stage/ambience retrieval), in my system/room and to my ears.

     Two 120’, twisted runs of  Southwire 10/2 AWG, SIMpull Romex (likewise: USA made), from the main breaker box, to the AC outlets.

                           NOPE (matching makes no difference, to me)!

I like all my 60 cycle hums to match.