It definitely could be of use to be able to disable players' macros (and maybe screenshot-taking) temporarily during certain activities (where using macros could be potentially exploited to have an unfair advantage). For example, during a minigame where you need to quickly execute certain actions or click certain buttons, or as such.

Thinking about it, another good candidate of a flag to add to control_freak would be to control the player's ability to use clicking client commands (including in macros), i.e. .click and .dblclick. You're not able to do this to a satisfying result currently (read: properly), and these commands' usage can be undesired as well as an exploit in many games.
(What could also be really nice is being able to control this on a per-atom basis (meaning by a var on /atom) instead of a global one, but that's more work)