Excluding section 273 from the application of the judicial discretion clause would leave those MMPs for those offences open to constitutional challenge and may have the effect of fewer offenders being subject to those MMPs. This is because it would be excluded from the ambit of proposed section 718.4, and they would be potentially subject to constitutional challenge on the basis of reasonable hypothetical scenarios.
If that MMP is struck down, it cannot be applied to anyone in the jurisdiction in which it's been struck down. Clause 63 would insulate the existing MMPs against constitutional challenge while also, as we've discussed previously, reviving MMPs that were previously struck down.