Is there an optimal interconnect lenght?

"Break-in" time and the time it takes to "settle-in" (Or "re-settle in" after being moved around) happens quicker in a shorter length IC. Nothing wrong in using a .5m Interconnect and will cost less as well.

For analog interconnects shorter is always better, unless, that is, it's too short to reach between the components. :-) That's basic electronics theory.

Anyone who tells you otherwise is advocating interconnects as tone controls.

The shortest is the best.

Remember: The longer the 'connection' the higher the resistance and the bigger the possibility that the cable will turn into a 'nasty' microphone. Yes- a microphone!

Cables don't "work" - their job is to transfer electrons between the components more or less perfectly. The longer the more difficult it is for the electrons to travel.
Different dielectrics & electron-carriers (copper, silver, carbon) may cause that cables sound different from eachother.

Best regards,
Dewald