I'm planning to give these nozzles a try. To repost your part # from the other thread, it's Monark 039 305 138.
It looks like MercedesSource has a pretty good deal on a pop tester for $179 also:
http://mercedessource.com/node/5180
It looks like something that could be homemade for under $100, but I'm kinda leery to do home experimentation with something so potentially dangerous as 2400psi diesel fuel.
Are you certain that the increased pop pressure causes a significant change in timing and injection quantity? This is a positive displacement pump, and diesel fuel is relatively incompressible. The timing specs on the D24 and D24T are also the same, despite the differences in pop pressure.