I recently discovered that qBittorrent essentially has a VPN Kill Switch feature built into the client which will kill its connection if it detects your VPN has disconnected. VPN kill switches from VPN clients for the desktop are not fully reliable as they can often fail and you can still connect to the internet with a unencrypted connection with your IP exposed.
I would like to purpose adding this feature in the browser settings on desktop. This way if your VPN disconnects, Brave will also lose internet access too. There has been many times my VPN disconnects without me knowing while I was browsing the web.
I would also like to suggest this feature to get placed in Chromium, this way all Chromium browsers such as Chromium, Ungoogled Chromium, Chrome, and Brave will get this feature.