Very good question. First of all, whoever has the majority, dictates the rules. No strong-worded, bolded, underscored, all-caps written rule can do anything to avoid being overwritten by a faction that has the support of the majority. So, there's only one possible real long-term solution: to ensure the support of the majority around Milei's reforms.

A majority educated on Milei's ideas will always penalize those who vote against the tenets. That strategy Milei calls "Principle of Revelation", by which he ensures that those who go against the will of the people are always publicly exposed. That permanent threat of negative electoral impact has allowed him to garner the votes of the opposition to pass his reforms, in despite of having a minority in the senate. And when they don't, people reacts furiously, specially the youth, which is an asset Milei also ponders to his advantage, for they are the future majority. A ticking bomb for the opposition.

To keep that strategy going, Milei knows, and states, that the "cultural battle" must be fought eternally, so that people never again let themselves fall on the hypnosis of socialist irrationality. To that effect he permanently delivers speeches, and has assembled a team of ideological referents, with the aim to expand it. One such initiatives is the "Lighthouse Foundation". He has also always been a supporter of the "Students For Liberty" foundation.

Of course, layers of legal obstruction are being crafted to attempt to slow down an attempt to revert the reforms. But ultimately the democratic majority is the only way to ensure they're respected long-term, and to that effect, people must be educated to support the reforms themselves, not just the middleman in the senate who does.