I remember when I was in the Auxiliary, if we were going to be working directly with the Coast Guard we were to take off our Flotilla Office Insignia and wear the basic Member insignia instead. This was when we worked the radios on base or on served on their boats and aircraft.
We don't get to use pin on insignia anymore. Some members tried to get by with Velcro and kept losing stuff. I have nothing but member insignia on all my ODU (equivalent to CAP's blue BDU) at this point.
Which, given my age - make me look like a full Commander from any more than about 8 ft away. We really should leave the collar insignia off altogether.