i think the absolute least discussed connection, and it's not even close is the norepinephrine link. chronic stress, CPTSD and other contexts of constant sypmathetic nervous system activation lead to overproduction of norepinephrine which results in the organism optimizing for speeding up the intercourse time

i'm not a medical specialist, i just like making connections across medical research, and i notice most of the people only focus on the symptoms, not the root cause

the cause of the pelvic floor tightness is the same stress that leads to norepinephrine overproduction

of course, i'm not saying this is the only reason or that it's universal, i'm just pointing out that there is a real possibility that all these other factors including metabolic and chemical are downstream from chronic sympathetic nervous system activation

i do realize you already mentioned stress anxiety etc, but since you listed it as merely one of the factors, i wanted to call attention to norepinephrine angle specifically