I have an idea the X-wind limit was 20 kts so anything that was not steady above 15 kts was ample justification for not streaming. Above 20 kts there was a danger of weather cocking.
Incidentally, remember the VTTS TV with them wearing safety harnesses on the wing. I never saw anyone with any safety gear although I believe some harnesses where available. The problem was the lack of sky hooks to hang from. Anyway a rigger was killed reloading a TBC.
Accepted practise was to sit on th eback of the cone, facing forwards, and closing the door using the turnscrew until it latched (not sure the right terms there). Anyway it failed to latch or the latch failed and the door sprang open flipping the rigger off the tail to land head-first on the concrete. I think everyone was a bit more cautious after that fatal but I still do not recall seeing any safety gear.