I'm just questioning if that blue atmosphere should be shown to killers.

Survivors have the exact notification of all hex perks. Thrill of the Hunt when cleansing a totem. Undying when they are close to a dull totem, etc.

All hex perks have the UI event notification, the exact notification (perk name).

So, why not to show the killers at least the aura range of boon totens? Honestly, killers need this map control, since the boon totens put too much pressure on them. Yes, hex totens put too much pressure on survivors, but once they are cleanse, they are deleted from the match.

I want to be clear, the killers still won't know what boon totem they are facing (unlike survivors with hex totens).