

Good question! I think this is distinct from split tunneling, but does a similar thing. But I’m not an expert - I don’t know how precise or broad the definitions are, so I’m not positive the concepts don’t overlap.
From some brief reading it looks like split tunneling is set up by configuring routing to determine which traffic goes through the VPN based on destination IP addresses. OTOH what I’m calling confinement determines VPN use based on which process sends traffic. So with confinement all traffic from select processes, regardless of destination, goes through the VPN.
I think there are differences in how inbound traffic works too. With confinement inbound traffic can only reach confined processes.





I’m very glad I switched. One of the little improvements: IIRC last time I checked PaperWM didn’t have bindings to set a window to a specified width. It only had a cycle width option. With Niri I have shortcuts to set a window to ¼, ⅓, ½, ⅔, or ¾ of the screen width.
There are lots of other improvements. One of my favorites is the dynamic screen cast target.