The MAC UI itself allows to assign a domain to always open in a specific container. If you need it more specific than an entire domain there are other extensions that can allow you to automate containers, but personally all I've needed are the domain-wide assignments.
Admittedly, I also tend to use unloaded tabs more than bookmarks, so if I need a very specific address in a specific container I am probably likely to just unload it but leave it open somewhere. (Sideberry "helps" me in this bad habit with multiple tab panels and tree grouping of tabs.)
Admittedly, I also tend to use unloaded tabs more than bookmarks, so if I need a very specific address in a specific container I am probably likely to just unload it but leave it open somewhere. (Sideberry "helps" me in this bad habit with multiple tab panels and tree grouping of tabs.)