In the case of tube circuits a centimeter or two of wire is in series with the conductors in the tube sockets and the pins up through their connections to the internal tube parts such as the plate not made of silver, the grid wires, and the cathode. These less than exotic signal paths are not considered an issue and they do little harm to the sound. The difference between more exotic less disruptive wires between tube socket terminals and other circuit elements makes the value of exotic wiring insignificant. In the case of resistors or capacitors or transformers which have their own wires connected to tube socket terminals you can't unroll a capacitor and replace the wires and re-roll the capacitor. You have to trust the capacitor manufacturer to choose the best wire. I think Mundorf can be trusted to use the best wire in their capacitors.
For transistors you have wires of the transistors you can connect directly to adjacent components. Otherwise, where you can replace wires, there might be no noticeable difference but for a foot of pure silver wire without insulation and ease of soldering is affordable and will not do any harm.