The answer to the text of the question is: that would continue to work. sudo doesn't re-auth while a child process is still running, which in this case is su. Until su terminates, sudo doesn't have anything to say about it. To be a bit more precise, the time limit for reauth would expire, but sudo doesn't ask for authorization, and therefore wouldn't check if that timeout has elapsed, until the next invocation.

To answer the spirit of the question: you should probably be using sudo -i instead.

as someone who has a similar setup of sudo needing reauth after a while, i can tell you that it’s really no issue. keep in mind it only prompts you for a password when using sudo, meaning it prompts you when you run sudo su, and then su is just running. for as long as su keeps running, you don’t need to rerun sudo su, meaning you don’t need to reauthenticate.

in other words. the reauthentication requirement will never kill any running processes. it just requires a password when running sudo.

edit: also, i would recommend sudo su - instead, because it makes sure you get the env vars that root uses. running sudo su has lead to lots of head scratching personally. (especially on debian where /sbin binaries are not in the path when using su without the dash)

There's always sudo -i, which starts a root shell. I imagine that's untouched.

That’s a configuration change. Distributions will decide differently and they can all decide something different. Not the same issue with BSD.

It's almost like you dream of pfexec.

Windows allows you to open cmd as an administrator, so all you do in that tab is as an admin. In assume something similar could don't, but obviously coukdnbe used for escalation attacks.