I guess the pax can press their face on these windows as a backup de-ice system.
Interesting to see what happens if a window pops out or in.
I recall the Mirage with its delta wing needed a very high rate of knots to glide to overcome the delta wing drag. Generally, gliding was only done during dead-stick practice (the figures are incredible) and normal approach required more than normal fuel burn to motor in than other non-delta wing craft.