I do 2.5G in a 5G ss stock pot. I add 1.5lbs of DME to it to do my hop additions. It doesn't foam up that much. The only time it foams like that is when we steep grains 1st,then add the DME(s). It usually foams about 3 minutes before dissipating. But the bigger pot def helps. You just have to stir like mad to keep it down for that 3 minutes.
Everything works if ya let it-Roady(meatloaf)