Macro to turn webcams on and off?

I use my MacBook Pro side-by-side with an Apple Cinema Display.

I don't use the webcams on either display too frequently, and I'd prefer to leave these webcams "off" in general and then only turn them "on" when I need them. (Note that by "off," I mean the webcams wouldn't be usable by any apps; I don't mean to suggest that my webcams are in use all the time.)

I know there's a way in MacOS System Preferences to select which apps have access to your webcam. So I suppose in theory you could regularly remove all the apps' access privileges and then add them back again. But that's impractical.

So I'm wondering if there a way to turn webcam access on and off for your entire system?

And, beyond that, I'm wondering if there's a way to then set this up to work by shortcut in KM?

Thanks in advance for any suggestions and ideas!

(Obviously, another alternative is to use camera covers, which I've done in the past, but I find these to be a bit unsightly, and I don't like the risk of their cracking or leaving residue on the screens.)