Jurors could interpret the first and second paragraphs of CC 358 to apply to both statements made by the defendant before trial and to the testimony of the defendant during trial. To clarify this potential ambiguity CC 358 could be modified to provide as follows [added language is bolded]:
[Para 1; sentence 1] You have heard evidence that the defendant made [an] oral or written statement[s] (before the trial started/while the court was not in session).
[Para 2] Consider with caution any statement made by (the/a) defendant before trial started …
Unless these modifications are made there is a danger that the jurors will not understand that the cautionary language does not apply to the defendant’s testimony at trial.
Regarding judge’s duty to give this instruction see this post: Cautionary Instruction on Defendant’s Statements Not Required Sua Sponte