Sure it does potentiate. it is a known fact that MXE potentiates opiates AND amphetamine-based stimulants (of which MDMA is one). I take MXE with MDMA all the time and know people that do also, its a fantastic combo as long as you are not irresponsible and you keep the dosages at around 60 mg of MDMA and 20 mg of mxe. Yes, I can roll very hard off 60 mg of MDMA which I would normally not feel what soever without mxe.
MXE potentiates amphetamines. ask anyone that has experience mixing the two
you must live in a cave if you've never heard of dealers putting things into drugs to make people get more fucked up even if it klls them? Why do dealers keep putting fentanyl into heroin and killing all their customers? it doesn't make any sense yet seems to be happening for a decade now.