The german blocks are actually designed for such a situation though (higher performance than normal at low flow rates). In fact I would hazard to say that the Innovatek kit seems to be one of the few that is optimized for the performance part of price/performance by the manufacturer.
The 3/8" tubing will limit flow rates (more or less) to 40-60 gph. So you can always take this limitation and work with that. Look at what sort of head the 1048 can produce at that flow rate and you'll have an idea of how much resistance you can put in your loop.
Owen from the o/cers forum had a simple and effective idea: insert a "T" before and after the pump, add tubing (high enough to avoid a geyser) and make a manometer.
Look at BillA's data for guidance:
With the knowledge that you will be on the left of the graph (low flow rates). My assumption is that the maze3 is no different from the cooltech maze type block; maybe we can get Bill to clarify...