I’ve purchase my own boots since 2008, like most of us at the Sqn. Never was I told I couldn’t wear them. My wife is a physiotherapist and the first thing she said when she saw the Air Force issued boots was not to wear those, they’ll destroy your feet, knees and back. Everyone’s feet are different and I’m a strong believer that you should be comfortable wearing the footwear that is right for you.
As for not being covered, I can personally testify that having been through a VAC claim, including the redress process, never was I asked if I was wearing issued kit, but again every cases are different and maybe someone may share a different story.