BV, I started fast jet flying a couple of years before BEagle and from 75 onwards flew 6000 hours on zero/zero ejection seats. If my memory serves me correctly we used the simple principle that if the canopy was down we were strapped in and seats live. If the canopy/canopies were open we were seat safe and unstrapped. On any bang seat it is implicit that the occupant makes the seat SAFE at a time when it can be ensured SAFELY. If it was essential to taxi back with the canopy open (due to excess temperatures) then we stopped for 15 seconds and safed up the seat safely. Yes, and for you younger ones we used to fly jets that did not have AirCon and cockpit temperature could reach 50°C+