There isn't a hard and fast rule for what goes into the box. We tried to go through the list of everything and make judgement calls. Very spammy things that you are grateful for but don't need to be reminded of constantly (say Replenishment) go in the box. Long-term buffs go into the box with a couple of exceptions. Things with relatively short ranges, like say totems or paladin auras, stay out of the box because you need to know if you move out of range of them. Things that are very core to your class, like Shadowform, paladin seals or warrior stances, stay out of the box. Inner Fire stays out because it has charges. Things like Inspiration and Heroism that might actually alter your behavior stay out. Anything related to a specific encounter will stay out of the box. If in doubt, we left it out.

The other new option, the castable debuffs, is a way to just see "your stuff" on a target, especially a raid boss. If you want to see your Corruption and CoA and not every lock's dots, it works well for that. It does not work well for debuffs that share the same exclusive category, like say Mangle and Trauma. That functionality is something we'd like to add in the future. If you're a raid leader, it's not going to let you see if all of the critical debuffs are being applied. But if you aren't a raid leader, don't have a lot of fancy mods to monitor such things, and just want to make sure your DK diseases are still up, it's great for that.

We find both new tools to be really useful, but they default to off, so we wanted to make sure players didn't miss them on the PTR while there was still some time to iterate on the design.