I only have useless foam for the one type of cider (which was likely overcarbed). Will let you know when I put a couple other kegs in if this issue occurs - I have ubu ale carbing up right now.
From my perspective, unless the ubu ale or other beers act like the cider, I am good to go. This would tell me the cider is overcarbed.
Remember, the porter was producing perfect pours after the first pour. And the first pour for the porter was perfectly acceptable, albeit slightly over foamed.
Guess what I am saying is - the setup works very well as is. With a tap, you just top off your beer as the foam works down (60seconds?), I don't dump the foam, so no wasted brew.
Since I just reinsulated - I will try to update any changes in a week, which is when the graff should be stabilized and less carbonated.
EDIT 1/11/2011:
Seems I overcarbed the Graff and the porter. I am getting routine pours from the tap with < .5 inches of foam. I did the rush method of carbing and it caught up with me. Just put in my UBU ale and it is performing well through the tap.
Conclusion being - the set up is working phenomonally well. I have been toying with temps, and working out the kinks in the system so if you are interested in the specs feel free to PM me.