This doesn’t work. (Recording is Linux Firefox; same thing happens in Android Chrome.)
An error is logged when I click a second time (and not when I click on a different probability):
[GraphQL error]: Message: null value in column "prediction" of relation "ElicitQuestionPredictions" violates not-null constraint, Location: line 2, col 3, Path: MakeElicitPrediction instrument.ts:129:35
In practice, it just requires hardware with limited functionality and physical security — hardware security modules exist.
An HSM-analogue for ML would be a piece of hardware that can have model weights loaded into its nonvolatile memory, can perform inference, but doesn’t provide a way to get the weights out. (If it’s secure enough against physical attack, it could also be used to run closed models on a user’s premises, etc.; there might be a market for that.)