Map Boss Skill Tree Feedback

I think you guys could put in the game a way to track Map Boss Skill Tree objectives... I'm at level 95 right now, killed all breach, expedition, ritual and abyss difficulties to get those points, but I really can't find what is missing to the 9th and 10th points of the Map Boss tree, I've already did everything on the list but I got the feeling something is bugged..
Already killed Arbiter, already killed citadel boss in 6mod T15 Waystone, already killed boss in 6mod T16 corrupted map Waystone, 6mod T16 rare Waystone, level 81+ Waystone and I just don't know what am I missing here...
In this case I think it would be good to have a tracking for these objectives so I could objectively go chase the one i'm missing.. By now it is just a try and fail until something works..

You need to kill one of the deadly boss with 6 mods T15 waystone.
The ones from interlude with special maps.

Not sure what else you would need other than that.

Yea I did kill deadly bosses in 6 mod T15 and 6 mod T16... Still don't know exactly what is missing and I think that is the point on the feedback I did... If I could track exactly what is missing, I could go straight for it..