You are correct in your description of the functionality of the cam integration into the HMS as Security Cams.
The Security Cams, and the corresponding Push Notifications from the HMS, are On Duty when the system is Armed to either Home or Away. The system currently lacks the capability to designate cams On Duty for each of the Armed states seperately.
I took a quick look at the Wishlist and did not find a topic that would match this request. I would suggest submitting a new thread in the Wishlist category asking that this feature be added.
Because the rule you set is turning off Cam Notifications and not HMS Security Notifications, you are still getting the Push Notifications from the HMS while the Cam Notifications are off. The only way to silence the HMS Notifications while in Home mode currently is to remove the cam from the Security Cams section or modify the rule to turn the cam Off while in Home mode. Neither is an adequate solution.
However, I have found that the Security Cam integration into the HMS adds no additional functionality to the cam. The cams already have the same AI detection and notification capability native to the cam features with Cam Plus. Adding a Cam Plus Cam to the HMS as a Security Cam just produces redundant notifications.
Another request that can be made is to add a post to the Wishlist thread below asking for the HMS Security Cam Push Notification Toggles to be added as Actions within the Wyze Rules.