I don't see how there could be a solution for a huge gap. I mean, if today, right this moment, a nuclear bomb landed somewhere, the people with bids on the market would immediately cut those bids in half (for example). There's simply no way to get out of a trade at the price that was there moments before ... no technology, no anything, the bids just changed, there's no do over for that. I don't see how anyone can "solve" that problem, it's fundamental to the way the market works. Like you said, the only thing you're left with at that point is some kind of a hedge, an options position of some kind or etc. Maybe there's a price point where the options are far enough out of the money that they aren't expensive, but would get fat and ready for harvest if the market gap was large enough to need them ? Out of the money and really close to expiration ?
You are right, there is no solution for this how you describe it. If you are long in a highly leveraged position, and a nuclear bomb is dropped somewhere, of course you will pay the price for the long position you took. This is the kind of risk that I am willing to accept, this is part of trading and cant be avoided, at least not 100%.
What I want to avoid is a situation in which I loose control when I should not have lost control. No extreme shock event or something like that, but loss of connection to broker, to exchange, datafeed, risks like those. These kind of risks can be avoided, and backup brokers, accounts and instruments are part of this.
If I loose control over my position in the market, even a regular non-farm payroll event with numbers that come very out of line could ruin me. Imagine 10 minutes before non-farm payrolls, I have a position of 80 contracts ES long and I receive a call from my broker that they have a technical problem and I cannot close my position. Non-farm payrolls are no shock event, but if you loose control over your account even such scheduled economic data could ruin you. This is the kind of risk that I want to eliminate. In the past I did this by using a second FCM as a backup. But this combination wont cover all these types of unnecessary risks. Therefore I am having a closer look at options now and will probably open a options trading account as additional backup.

