If the device is known to the user, then the "Add as Known" button takes care of adding that device as known and all 3 of the warnings should disappear.
If "Add as Known" isn't wanted, then there should be another button called "Remove Connection" for each that uses the API to the device in question and removes the sharing of the tephramesh Syncthing folder to the other device.
In the example, pressing the "Remove Connection" button for the first warning would use the API to the MacBook Pro and remove the sharing of the folder to the iPhone 14 Pro.
Show the "Add as Known" button in blue and the "Remove Connection" in yellow.

If the device is known to the user, then the "Add as Known" button takes care of adding that device as known and all 3 of the warnings should disappear.
If "Add as Known" isn't wanted, then there should be another button called "Remove Connection" for each that uses the API to the device in question and removes the sharing of the tephramesh Syncthing folder to the other device.
In the example, pressing the "Remove Connection" button for the first warning would use the API to the MacBook Pro and remove the sharing of the folder to the iPhone 14 Pro.
Show the "Add as Known" button in blue and the "Remove Connection" in yellow.