Privacy News Microsoft built a dedicated app that forces Bing everywhere on Windows 11, including Chrome, Firefox, and Brave

Yes, that is a much safer way, instead of messing with the registry each time.
And it works in Linux as well (not that I expect MS to push this cr*p to my main OS).
I have now put this in policies.json and it worked:

Code:
{
"policies": {
"ExtensionSettings": {
"*": {
"blocked_install_message": "This extension has been blocked by your administrator."
},
"{8d8ca802-6b23-43ed-9445-e05d48579542}": {
"installation_mode": "blocked"
},
"{a07b7886-3015-4959-9a88-4273860edd6d}": {
"installation_mode": "blocked"
}
}
}
}

Yes, I notice you've added another policy for the second,in my opinion, unlikely,extension because it doesn't match the one for Chromium-based browsers.
If you want, you can also omit the optional opening part; as my screenshot shows, the policy works just the same.

I'll include my JSON file here, which, as you can see, contains four policies in abbreviated form,this should also be helpful to other forum users ;):



Code:
{
  "policies": {
    "OverridePostUpdatePage": "",
    "DontCheckDefaultBrowser": true,
    "OverrideFirstRunPage": "",
    "ExtensionSettings": {
      "{a07b7886-3015-4959-9a88-4273860edd6d}": {
        "installation_mode": "blocked"
      }
    }
  }
}

Note that, in my case, if I were to add a fifth policy, I would have to put a “,” after the last policy.
 
Yes, that is a much safer way, instead of messing with the registry each time.
And it works in Linux as well (not that I expect MS to push this cr*p to my main OS).
I have now put this in policies.json and it worked:

Code:
{
"policies": {
"ExtensionSettings": {
"*": {
"blocked_install_message": "This extension has been blocked by your administrator."
},
"{8d8ca802-6b23-43ed-9445-e05d48579542}": {
"installation_mode": "blocked"
},
"{a07b7886-3015-4959-9a88-4273860edd6d}": {
"installation_mode": "blocked"
}
}
}
}
You are using Edge on Linux?
 
I think it's wrong that we have to tweak and babysit MS so much. MS updates and changes always either break parts of the OS or they are just plain unwelcome. MS just keeps pushing things too far. We should not be in a constant battle trying to mitigate and manage their useless and egregious changes. I am really considering going to Linux Mint full time now. I have just about had enough of MS.

C.H.