Graham, if anything are they okay with using POM for the shoulder hinges? I would prefer metal, or a return to the 1/48 style backplate/shoulder hinges. On those ones, even if you push the hinges through the "stopper/bumps", the hinges will NOT break. I have done this many times on the 1/48 1S Hikaru I have, always thinking this is the way the arms are supposed to be swiveled from fighter to gerwalk, and have YET to have a breakage. Bear in mind my 1S Hikaru is now 7 years old, and those hinges aren't going to break in the forseeable future.
The best thing about the v2 1/60 shoulders is the tightness, unlike the 1/48, the ball joints do not feel prone to looseness over time. However the hinges themselves are better on the 1/48. Similar in function and look but the major exception being the lack of breakages on the 1/48 shoulder hinges.
The easy way out of this is to use diecast shoulder hinges on the v2 1/60, or at least POM.