This is an excellent overview of hypersonic propulsion. It is interesting that Director calls this "disruptive technology". He also touches briefly on scaling up X-51 by 100X and how hypersonic propulsion can be used for launch with "aircraft like" operations. The charts, while pretty cool, do not mention anything about the possible stratospheric effects of burning hydrocarbon fuel at 25 km altitude.
As you can see from the plot 25 km is right in the middle of the ozone layer. But ozone chemistry is tricky and sometimes adding one ozone destroying molecule just chemically ties up another and results in a decrease in ozone destruction. This is how subsonic aircraft cause an ozone increase.
Will hypersonic propulsion do that too? Or will they cause ozone loss? How much gain or loss?