Phantasmal Killer has the same "descriptive" part of its name as the similar spell Phantasmal Force.
The key points of Phantasmal Force are (PHB p264):
You craft an illusion that takes root in the mind of a creature that you can see within range.
The phantasm includes sound, temperature, and other stimuli, also evident only to the creature.
This means that the significantly lower level spell Phantasmal Force is inescapable by being blind or otherwise sensorily impaired compared to the RAW description of Phantasmal Killer. The target experiences the Phantasmal Force illusion even if all their senses are somehow switched off. It is all in their mind and the effected target will rationalise even obvious inconstancies ("My totally destroyed eyes must still be able to see ghosts! Arrrrg!").
Phantasmal Killer does not have this in it's description (PHB p265):
You tap into the nightmares of a creature you can see within range and create an illusory manifestation of its deepest fears, visible only to that creature. The target must make a Wisdom saving throw. On a failed save, the target becomes frightened for the duration. At the start of each of the target’s turns before the spell ends, the target must succeed on a Wisdom saving throw or take 4d10 psychic damage. On a successful save, the spell ends.
However working in a similar way to Phantasmal Force is perhaps implied by it's name, the single target, the "feel" of it's the description and the way it inflicts psychic damage as time goes on. Historically (AD&D Illusionist spell) and in other branches of D&D it is clear that this spell works in this manner. In Pathfinder (Pathfinder wizard/sorcerer spell) Phantasmal Killer is a spell of type phantasm which has rules of its own, specifying it all happens inside of the target's head.
The question: Should Phantasmal Killer work the same way as Phantasmal Force (and perhaps be modified in some canonical source?)
Is the difference in detail in the spell text a deliberate part of the spell design, or an oversight in bringing the spell forward from previous versions?
I can't find any existing errata or sage advice on this.
Running Phantasmal Killer the same way as Phantasmal Force is my group's preference for the spell and the house rule for running it when I am DM
This question is related to a previous question which any answer should consider first: Does Phantasmal Killer work on a blind target