DXM is the only NE reuptake inhibitor strong enough to make me flat out panic for hours, and that was without any combination. Given that 2mg d-Amph were enough to increase my blood pressure by an awful lot while on moclobemide (clonidine works to relieve that btw), and the fact serotonin syndrome doesnt exactly sound fun, also people got it from just DXM + SSRI, really I wouldn't mess with it.
We need some weak / partial MAOIs though and based on my experiences with 4,4'-dmar, this could make very interesting combos and possibly help to make SSRIs finally more effective than placebo in serious depression / anxiety.