I have not used AudioQuest in years so I can’t give any input on their cables, but use their Edison outlets and am very happy with them. I’m sure the AQ cables are great nonetheless. In my experience with much older generation such as Lapis, Diamond and Sterling, they did not muddy the sound.
I use Frey 2 speaker, XLR IC’s and in my system they sound great. I did bring home a Heimdall 2 XLR to compare to my Frey 2 and took them back - the Frey 2 to my ears was superior . If you enjoy your current Heimdall, I would be surprised if you didn’t find the Frey 2 an improvement. In the Nordost line that is probably as far as I’d go with your system, as not sure the money for Tyr would make sense.