I just had to try this combination just one time. So, I took 100 mg of 4-FA, and one hour later, 110 mg of mdma.
Chewed the largest hole in my tongue anyone had ever seen. Bled like a stuck hog.
Other than that, I don't remember a thing for the first 90 minutes. The person I was with took video of me talking with people. I was embarrassed at my demeanor when I watched it the next day.
Oh - And, my heart rate was over 100 for the next 10 hours.
Thankfully, I had no comedown problems at all. (But, I never have.)
*IF* I were ever to try this combination again, I'd try something in the mg ranges that Folley suggested above.