Not necessarily a hot-take, but maybe outside the norm:
What if PyroVision isn't literal. What if it's just a visualizer for the state of euphoria Pyro enters while committing arson. There are times in the comics- for instance- where it could be argued he's processing the world more or less as we, the audience, do: We can't see through his eyes, he may not be experiencing hallucinations and/or delusions in that moment.
I do live for him having schizophrenia, but imagine if he uses very colorful, cheerful language to describe what he knows is violence.
In the world of TF2, there's nothing to say he can't be a successful CEO and be experiencing 24/7 hallucinations, but what if the arousal (psychological definition, not standard parlance) of combat triggers his hallucinations?
I admittedly don't know nearly as much on the subject as I'd like to, but this's something I've been batting around for a while