the different lines of research are not mutually exclusive. Everything helps
Its going to be a mistake to assume that PFS/PAS/PSSD all have the exact same mechanism behind them. Its possible that they might, but there is literally no reason to confidently assume that this is the case. To give you an example of this I will provide an excerpt from the very page you linked (which has awful and hard to read punctuation btw):
Serotonin REDUCES PPARy which normally ACTS to INITIATE Androgen Receptor (AR) activities; that’s WHY we get DOWNREGULATION of androgen receptors with SSRI - because the “nuclear” receptor of PPARy is being downregulated (persistently) by SSRI’s - which causes a continual reduction in Androgen Receptor amounts (densities) and activities. SSRI’s like Luvox & Prozac “get in the middle” and cut off the “supply and demand” connection to nNOS from the Androgen Receptor - leading to LESS neuronal nitric oxide synthase and NO non-contact erections (erections without touch). STUDY -->
It is well known that PFS is associated with the androgen receptors being overly dense and upregulated, NOT with them being not dense enough and overly downregulated. From the page you posted alone its clear that the etiology of PSSD is different than that of PFS. Im all for cross research into PFS/PAS/PSSD but I disagree with this idea that PFS/PAS/PSSD must definitely have a common cause.