Here is VXN in September 2001. VXN did not jump 15 points. It jumped 25 points, came back down and jumped up another 25 points again, not to mention the VXN move higher since SEPT 1st low of 55. If you had SEPT positions and a now long options, you had almost a 80% increase in vols on a spike. And it was before expiration in Sept.
I want to reiterate that this is for major Black Swan. Katrina was not a Black Swan or huge crash so Vols only moved close to 20 and this is not what you are hedging against. Simple adjustments will hedge against these type of moves or just getting out.
Here is the SPX move in the same time on 9-11 frame as the VXN (notice how the market dropped some 35 points or so before 9/11 causing VXN to increase, a hedge was needed even before 9/11 as the market was falling since AUG)
But a 9/11 where the market falls hard and VIX spikes is where the hedge will be a huge band-aid for ya. VIX was not before 2004 so I am using VXN here but the results would have been similar. Notice how hte market was falling hard before 9/11 so a SEPT spread would have had some protection from SEP VIX calls (if they existed) purchased in AUG.
NOW look at 2002 crash in SPX:
AND compare it to VXN in the same time period:
It is possible that hedging with VIX (if they existed at the time) woudl have helped hedge somewhat those JULY and SEPT/OCT drops.
It is looking out into the future, but the VIX options present a viable way of hedging against huge market drops that are sudden and swift which cause VIX to spike. Slow bleeds lower like post-Katrina are different and require the hedges we talk about frequently. But this gives you another choice or "option" to look into. Not saying it will work 100%, but past crash activity leads me to believe it is worth the cheap price right now of insurance with the VIX at all time lows.
Any gains in the VIX calls will offset losses in the spread, if you have to take any. With a spike those calls will have some value. Even if the $0.30 call goes to $5.30, my exmaple of 120 calls is $60,000 net profit against your spread position.