For what it's worth, most people saw problems with the Foma 200 film in 120 format, a few reports on the Foma 100, and I can't remember any complaints about the 400.
About agitation: The purpose of agitation is to bring fresh developer in contact with ALL of the film area in the tank, at the same time. If your agitation is too slow, then you run the risk of uneven developing, and if it's too fast, you could see edges of your negatives more developed than the center of the film.
A happy medium is best, where you need to make sure of the following:
1. Do NOT completely fill the tank, because if it's completely full, the developer will not flow inside the tank to properly mix the developer up before you set it to rest again.
2. Do full inversions, but do it fairly slowly, like one full inversion in about three seconds or so.
3. Do not shake the tank.
4. Tap the tank before you set it down to rid with air bubbles trapped on the film surface.
I had lots of problems with uneven development in 2008, and my actions above solved all of them.