If I'm not mistaken, customers have little idea that a price surge is in effect and what the rate is until they get billed. It's not like going to a gas station, seeing a price, and being able to opt in to the transaction, seek alternatives, or plan to self ration your consumption, as you're prepaying for the energy. The way the Texas model works it seems to assume that customers have a financial buffer that they're able to tap into to pay the higher rates. Everyone should plan for such a buffer but for those that don't have one it places hardship on them. It's also a risk for the provider that they won't get paid their windfall. You can't send huge surprise bills and expect people to pay them.
A sensible approach is to charge a bit extra under normal conditions to build a communal buffer that is used to pay for emergency power production. As long as there's good governance, this derisks the system. Another alternative might be energy bill insurance, if such a thing exists. It's easier to plan for a fixed monthly premium than a surprise payment in an emergency.