Use a second primary regulator (you can connect several primary bodies together by connecting the second regulator to the place where the high pressure gauge of the first regulator sits - move the gauge to the last regulator in line) to give higher pressure on the Belgian keg gas line, and install a restrictor in the beer out dip tube of the Belgian's keg to give more resistance.
I believe that's the conclusion from the thread. I don't know about food safety for sure, but undyed plastics are generally a better bet than colored ones. There are a couple of other options (one fits on the back of the tap shank) in that thread which are designed for beer use if you are worried about that.