and how exactly is that different from how N/DRIs work?
It's not.
Reuptake inhibitors are stopping these neurotransmitters from leaving the synapse, which creates a sort of "wall" blocking them from reaching the proper receptor. This is going to be the same between N/DRIs and SSRIs, although obviously the SSRIs will have a larger dulling effect as MDMA's main route of action is through serotonin.
This pretty much answers why DA/NE stimulants will still work with MDMA. There are still lots of DA/NE sites available for the chemicals, unlike 5-HT which is saturated.
Dopamine and Norepinephrine are VERY important for the MDMA high as well, however. There is no drug that will fully "block" MDMA's effects, but a drug like ethylphenidate should not be combined with MDMA.
Important to the experience - yes. But don't forget one theory suggests that DA release is actually an indirect result of 5-HT2 activation. This would further stress the importance of MDMA's effect on serotonin for producing the other weaker effects of the drug. I agree that MDMA should not be combined with ethylphenidate, but it certainly shouldn't
as you previously suggested.decrease the dopaminergic response dulling the effects of both drugs.