This is great info. I have the same issue with my 10x42 SLCs. Thanks!I too had a squeaking issue with my harness and e-mailed marsupial. Their suggestion was to stretch it a bit by either putting a slightly larger pair of binos in it, or by wrapping my binos in a shirt and stuffing it in.
I wrapped my binos in a pair of long johns and then threw a balaclava around it for good measure and stuffed em in the pouch for 24 hours. Now they slide in/out extremely easy with no squeak.
Little bit weird but it worked so I won't complain.
For reference that was 10x42 SLCs in a small non-enclosed magnetic pouch. They had previously fit my small no-mag pouch with no issues. The issue was made worse by the wind check and archery release on the sides of the pouch, but again I did that with my previous pouch with no issues.