ratio of non diastatic malt powder to one pound of flour.
The King Arthur Flour bagel recipe, the only one I could find that used non-diastatic malt power instead of malt syrup, has a ratio of 5.75 cups of flour to 1/4 cup malt powder to 2Tbs sugar and 1 Tbs salt.   

By weight, that works out to a Flour:Malt:Sugar:Salt ratio of 25:1.4:0.8:0.6.  So for 50lbs of flour, you'd want:


2.8lbs malt powder
1.6lbs sugar
1.2lbs salt


... which is a bit more than the "super bagel mix" of 2.5 lbs, in fact more that twice as much.  You can cut the amounts in half, but I'm not sure that will work out.  Good luck!