Breathing has it’s positive effects on some issues, but it doesn’t build general perceptive awareness. Part of what makes breathing a tool to deal with an emotion like fear is that it’s harder to feel the fear and the breathing at the same time.
To build general perceptive awareness slow movement that’s exploritive in nature instead of focused on having to express a fixed form, seems to me the way to build it. There are a variety of methologies that do this and somatics is a term coined by Thomas Hanna for them.
There are claims in Korzybski’s Science and Sanity (the book that coinend the map is not the territory) that schizopheria is due to dealing to much with abstraction instead of base reality and that conflicts of abstractions are partly the cause of the problems.
Steve Andreas makes a more specific claim that schizophrenia often comes with schizopherics having a self identity of not having quality X, Y and Z instead of positively having specific qualities.
Those neurolinguistic approaches don’t have peer reviewed evidence to back them up as they aren’t studied by academics but they have a community of practice behind them.
This kind of work is also likely benefitial to becoming less fragile in Taleb’s sense.
One word of caution: If you help someone to feel their emotions better, they can have an increased sense of agency in a state where they also feel strong negative emotions. So it’s good when they have a stable enviroment around them.
From a more Talebian perspective I wouldn’t expect modafinil and MDMA to increase resilience.