The original Lemo adapter sold by Mark Levinson is very well built and will not degrade the signal more than the thousand tweaks you are not using in your system :-) . IMHO using the adapter is better than re-terminating the cable with Lemo connectors that usually are not suitable for thick audio interconnects.
Anything you change can degrade performance, but the real question is how much?
Anything you change can degrade performance, but the real question is how much?