I wanted a way to update all device BLF Key Labels when you changed the name associated with an extension. I wanted to only update the name of the extension in one place and have that value updated on every device that has that extension assigned as a BLF.
So now when you edit the "Effective Caller ID Name" of an extension it updates the "Label" of every device that has that extension as a BLF.
I accomplished this by editing the PHP of the "Extension" page. in "Advanced" > "PHP Editor" edit the following file: /var/www/fusionpbx/app/extensions/extension_edit.php
After the section with the remarks of "//update devices having extension assigned to line(s) with new password" I added the following:

Obviously click save at the top and you're done.
I am not a developer by any means so there may be a better way to do this, but it works for me.
So now when you edit the "Effective Caller ID Name" of an extension it updates the "Label" of every device that has that extension as a BLF.
I accomplished this by editing the PHP of the "Extension" page. in "Advanced" > "PHP Editor" edit the following file: /var/www/fusionpbx/app/extensions/extension_edit.php
After the section with the remarks of "//update devices having extension assigned to line(s) with new password" I added the following:
This is what mine looks like://update device key label
if (strlen($effective_caller_id_name) > 0) {$sql = "update v_device_keys set ";$sql .= "device_key_label = '".$effective_caller_id_name."' ";$sql .= "where domain_uuid = '".$_SESSION['domain_uuid']."' ";$sql .= "and device_key_value = '".$extension."' ";$db->exec(check_sql($sql));unset($sql);}

Obviously click save at the top and you're done.
I am not a developer by any means so there may be a better way to do this, but it works for me.