As far as those outcomes goes, I don't think we are adequately tracking this, for covid-19 or for other health concerns. I have zero idea how much of this influences things with covid-19, which is why I am raising these questions. I'm more interested in seeing that these questions are asked, and whatever answers we find, they are what they are.
My own personal experience is that "psychosomatic" as a term has been used to dismiss or handwave those poorly understood mechanisms -- not necessarily with covid-19 specifically, but more in general. I'm similar to other DIY body hackers, but I work more along the lines of working with consciousness rather than something like DIY gene therapy. Some of my personal experiments yielded some results, and some have not. It's part of why these questions came up for me.
If I inject harmless saline into your veins and tell you it's poison and will slowly kill you, you will have a physiological negative reaction if you believe me, even though the saline does nothing to change your biochemistry except some minor dilution. Your firm belief will trigger (via poorly understood subconscious processes) autonomous responses that will fight an attack on your system that isn't there. It's extremely unlikely you'll die from something like that, but we've known about the placebo effect for a while now, and the nocibo effect (a negative reaction because the patient believes the treatment causes harm) is also demonstrated in the literature.
I don't doubt that some of the public reports of negative effects from the vaccine are psychosomatic nocebo effect. This is exactly why raw VAERS statistics are a terrible source of information about the actual biological effect of a vaccine intervention... Without further information, you can't disambiguate negative or positive outcomes caused biologically by the vaccine contents from negative or positive outcomes caused by psychosomatic reaction.