It's 100% a game mechanic that is too difficult and unrewarding to do during the campaign. Not sure if that's by design, but I'm not a fan. But in all honesty none of the league mechanics have been overly rewarding in the campaign since Ultimatum. Kalandra was nice for uniques, but they didn't juice the currency until later. Arch Nem you just didn't want to do anything. Sentinel was okay, but you didn't have really good Sentinels/Sent Skills until late game so occasionally you'd blast the wrong pack and couldn't kill them.
It is really weird though. Now that I've got an established character I'd rather run Sanctum for less rewards than blast red maps for gauranteed chaos because they made it really fun. I wish I could encounter more than one at a time or save 4 per map or something. Especially since you need to probably beat floor 4 boss for Sancitified Relics, which are the global ones. I've beaten her once at 75+, but just got a normal relic.
For those wondering about Volcanic Fissure totems:
They're okay. Definitely doable but clearing with them is a pain compared to Conc Path. At the high end on bosses, with +3 total proj, they're probably higher dps than Conc path for slow fatties. They're not bad for slow waves such as Blight and choke holded Breach portals. The only way to scale Fissure speed itself is a helm enchant which totem boys would want 18% Ancestral Protector speed on AND the other helm enchant is +2 Proj which is nuts. Definitely going to be some people who make boss destroyers out of them. Heard of people using Focused Ballista too which should allow you to pre-fire bosses, but the problem is you have to manually trigger an attack to tell your totems to attack which is annoying as fuck. Overall Conc Path is going to be the easier, better choice for about 80% of content, but VF totems will definitely have their niche and you can more or less just swap the gem out for these situations. Rain of Splinters is currently like 6 Divine (lol) so you'd probably swap that in and out too for a good rare jewel, but I'd give it another week or so before we see the PoEbrains post some ridiculous shit with VF. I think it ACTUALLY may be a really good self-casted slam if you just scale proj shit, but we'll see.
Really curious what the Raider build for Sanctum is going to be. Totems are great there, but their activation range seems REALLY buggy right now and sometimes they'll just sit and stare at a mob until you run into it even if it's active. Whatever it is hopefully it's a very clean looking skill (not spark) like Arc or something so you can still dodge mechanics while it's blasting. Meatball totems are definitely not good in that department.