Thank you - yes, I did find that interesting.
I’m embarassed to say that as somebody who once served as a protocol expert in the Australian Defence Force, I have no idea if there’s any similar tradition here, but I think it’s a good one (Australian Governors General who are retired officers (and many have been) have often worn their uniform, and others used to wear a British style uniform many years ago, but I’ve no idea if we’ve ever had an Australian uniform specifically for a GG. I inetend to ask - they are the Commander-In-Chief and there are situations where it would be appropriate).