Yes, except that in camera meetings should be restricted to matters relating to the protection of informants and the conduct of investigations following review of the situation by MPs and experts. In other words, they should be the exception, rather than the rule. Having a small committee of politicians conducting ongoing overview of the way in which these sections are enforced could indeed be useful.
Politicians may have some reservations about holding in camera meetings, and I understand that, since I have some of the same reservations. On the other hand, in the circumstances, one should be able to expect, not necessarily control, but some political responsibility or accountability. That's how I feel.
Of course, I am using the word “control” in the sense of monitoring or oversight, as opposed to decision-making. It goes without saying that politicians cannot decide the reasons for the investigation. That is not their role. On the other hand, they can act as watchdogs to a certain extent.