As the saying goes: “Play stupid games, win stupid prizes.”
Maybe include language in your trust disinheriting beneficiaries if they accept experimental gene therapy injections for themselves, or administer them to their children, or at least strongly incentivize them against that?
Given what we’ve seen over the last several years, I could definitely see some court ruling such a clause void as against public policy.
But the advantage of a trust is that you stand a better chance of not having the courts involved at all. Trusts are meant to be private, and your family may find a way to carry on your wishes no matter how a court may rule. Call it family justice.