Gluetun works great for other docker containers. For regular apps Vopono is another great solution, which makes it easy to for example run another instance of a browser in a separate namespace.

Check out Clonezilla, which is the perfect tool for the job.

https://mullvad.net/en/blog/2023/8/9/response-to-tunnelcrack-vulnerability-disclosure/ is Mullvad’s response to this topic. TLDR not a concern other than possibly for IOS.